tag:theconversation.com,2011:/global/topics/common-cold-5459/articlesCommon cold – The Conversation2023-11-01T11:43:27Ztag:theconversation.com,2011:article/2165592023-11-01T11:43:27Z2023-11-01T11:43:27ZIs it a cold, flu or hay fever? How to tell symptoms apart – and boost your immune system<figure><img src="https://images.theconversation.com/files/557073/original/file-20231101-29-xjh9ax.jpg?ixlib=rb-1.1.0&rect=30%2C0%2C6826%2C4585&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Many hay fever and cold symptoms in particular overlap.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/picture-showing-sick-woman-sneezing-home-1398519638">Dragana Gordic/ Shutterstock</a></span></figcaption></figure><p>As the crisp autumn air sets in and leaves turn to shades of red and gold, many of us eagerly anticipate the seasonal delights that come with the autumn and winter months. But, for some, these seasons also bring an unwelcome guest: <a href="https://www.nhs.uk/conditions/hay-fever/">hay fever</a>. </p>
<p>Hay fever is often associated with spring and summer. But <a href="https://www.immunology.theclinics.com/article/S0889-8561(20)30063-1/fulltext">climate change</a> means hay fever season now extends well into autumn and winter. This is due to climate change shifting weather patterns and temperatures, causing <a href="https://www.pnas.org/doi/10.1073/pnas.2013284118">extended periods</a> of pollen production from various <a href="https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1365-2222.2004.02061.x?casa_token=6cFhOAmSvQkAAAAA:w6_m5iO6NgO03UiUK9hd3MwgkM2SLut6rvhxWUhXUoJiO7RqwnaYpLQRs04-jGO33qYpNhdt6ypcfFdm">plant species</a>.</p>
<p>This shift in <a href="https://www.nature.com/articles/s41467-022-28764-0">hay fever season</a> is not just annoying for sufferers. It also makes it particularly confusing in the colder months, when colds and the flu are rife, to determine what’s causing your symptoms, since they so often overlap. This also makes it difficult to know which treatment will work best for your ailment. </p>
<h2>How symptoms compare</h2>
<p>Although there are several overlapping symptoms, there are a few key symptoms that can help you distinguish between colds, flu and hay fever:</p>
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<p>Symptoms such as sneezing and a runny or stuffy nose are common in both hay fever and a cold.</p>
<p>But if you also have itchy, red, watery or puffy eyes and an itchy throat, you probably have hay fever. These symptoms are much less common with a cold. If your throat feels sore and you also have a cough, you probably have a cold.</p>
<p>Flu symptoms rarely crossover with hay fever symptoms – though they do with colds.</p>
<p>A cough is the most common crossover symptom between a cold and the flu. Other symptoms, such as a sore throat, sneezing or a runny nose, can sometimes happen with the flu – though it’s less common.</p>
<p>Likewise, chills, fatigue and body aches – which are common with the flu – can sometimes occur in people who have a cold, though this is less typical.</p>
<figure class="align-center ">
<img alt="A man with a fever checks his temperature while lying on a couch." src="https://images.theconversation.com/files/557074/original/file-20231101-27-9niwf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/557074/original/file-20231101-27-9niwf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/557074/original/file-20231101-27-9niwf.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/557074/original/file-20231101-27-9niwf.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/557074/original/file-20231101-27-9niwf.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/557074/original/file-20231101-27-9niwf.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/557074/original/file-20231101-27-9niwf.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Fever is a telltale sign of the flu.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/high-temperature-concept-man-feels-badly-1483258463">juliaap/ Shutterstock</a></span>
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<p>The best way to differentiate a cold and the flu is if you have a fever – and if you’re experiencing gastrointestinal symptoms, such as vomiting or diarrhoea, which can sometimes occur with the flu.</p>
<p>Another symptom to look out for is temporary loss of smell and taste. While this can occur due to hay fever, it’s usually accompanied by a blocked nose. If you find you have a loss of smell or taste but your nose isn’t blocked, you probably have a cold of the flu. </p>
<h2>Supporting your immune system</h2>
<p>Since no one wants to be struck down by a cold, the flu or hayfever, the best thing you can to to prevent symptoms is boost your immune system using science-backed strategies: </p>
<ol>
<li><p><strong>Bolster your gut:</strong> A diet rich in amino acids, vitamins, minerals and fibre is crucial for both your <a href="https://theconversation.com/colds-flu-and-covid-how-diet-and-lifestyle-can-boost-your-immune-system-197151">immune system</a> as these are the essential building blocks of immune cells. A <a href="https://www.mdpi.com/1422-0067/19/12/3720">Mediterranean-style diet</a> is shown to be beneficial for the immune system for this reason. This diet contains plenty of fruits, vegetables, whole grains, nuts and seeds, and protein sources like fish, meat or plant-based alternatives. Additionally, consider <a href="https://www.tandfonline.com/doi/full/10.1080/19490976.2021.2018899">incorporating probiotics</a> to support your immune health – especially specific blends containing <em>Lactobacillus</em> or <em>Bifidobacterium</em>, which may potentially <a href="https://www.sciencedirect.com/science/article/pii/S2225411022000608#:%7E:text=Numerous%20studies%20show%20that%20some,on%20innate%20and%20adaptive%20immunity.&text=Upon%20viral%20infection%2C%20innate%20immunity,first%20line%20of%20host%20defense">benefit immune response</a> and reduce infection severity. </p></li>
<li><p><strong>Avoid smoking and alcohol:</strong> <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5352117/">Smoking</a> and <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4590612/">excessive alcohol consumption</a> are both shown to weaken immune defences. Even just five or six drinks on a night out can <a href="https://www.niaaa.nih.gov/alcohols-effects-health/alcohols-effects-body">suppress the immune system</a> for up to 24 hours.</p></li>
<li><p><strong>Prioritise sleep:</strong> Sleep is important for <a href="https://onlinelibrary.wiley.com/doi/10.1111/jsr.12096">maintaining immune function</a> as it reduces inflammation in the body. Aim to get more at least seven hours a night. Less than this may <a href="https://www.nature.com/articles/s42003-021-02825-4">increase your likelihood</a> of suffering from <a href="https://onlinelibrary.wiley.com/doi/10.1111/jsr.12096">common illnesses</a>.</p></li>
<li><p><strong>Manage stress:</strong> The stress hormone cortisol negatively affects immune cells, altering their function. It also increases histamine levels in the bloodstream, worsening allergy symptoms. <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4940234">Practicing mindfulness</a> may help manage your stress – and boost your immune system. </p></li>
<li><p><strong>Exercise:</strong> <a href="https://journals.physiology.org/doi/full/10.1152/physrev.2000.80.3.1055?rfr_dat=cr_pub++0pubmed&url_ver=Z39.88-2003&rfr_id=ori%3Arid%3Acrossref.org">Moderate-intensity physical activity</a> (such as a brisk walk or ballroom dancing) can improve your immune response. But it’s important to strike the right balance as long, intense exercise without rest between workouts can actually worsen immune function. According to <a href="https://journals.physiology.org/doi/full/10.1152/physrev.2000.80.3.1055?rfr_dat=cr_pub++0pubmed&url_ver=Z39.88-2003&rfr_id=ori%3Arid%3Acrossref.org">some data</a>, this decrease can happen after only 90 minutes of moderate- to high-intensity physical activity.</p></li>
<li><p><strong>Get your jab:</strong> <a href="https://www.who.int/news-room/questions-and-answers/item/vaccines-and-immunization-what-is-vaccination">Vaccination is vital</a>. But since you can only vaccinate yourself against the influenza virus, other <a href="https://www.gov.uk/government/publications/health-protection-in-schools-and-other-childcare-facilities/preventing-and-controlling-infections">preventive measures</a> – such as washing your hands and wearing a mask in busy, indoor spaces – can protect you against both colds and the flu.</p></li>
</ol>
<p>If you’re someone who typically experiences hay fever, you may also want to use some additional measures to prevent symptoms:</p>
<ol>
<li><p><strong>Avoid allergens:</strong> Steer clear of allergens that trigger symptoms. On high pollen count days, consider <a href="https://www.nhs.uk/conditions/hay-fever/">staying indoors</a>, keeping <a href="https://pubmed.ncbi.nlm.nih.gov/15452918/">windows shut</a> and using <a href="https://www.sciencedirect.com/science/article/abs/pii/S0091674909013177?casa_token=CkTL0kWie5kAAAAA:yvBLfFgn9XJPlenxxkLdy4zPxxbXRorx0dDamOIaE6oYYlg4o_o0xn4Ay9IzbhcsJSpF1dE">HEPA filters</a> indoors or an <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8431835/">N95 mask</a> to filter pollen particles.</p></li>
<li><p><strong>Antihistamines:</strong> Over-the-counter antihistamines, such as <a href="https://www.nhs.uk/medicines/cetirizine/">cetirisine</a> or <a href="https://www.nhs.uk/medicines/loratadine/">loratadine</a>, can be effective in <a href="https://link.springer.com/article/10.2165/00003495-200666180-00004">managing hay fever symptoms</a>. These should ideally be taken before exposure to allergens, and continued as long as symptoms last. Be sure to consult with your doctor for guidance before use.</p></li>
<li><p><strong>Consider immunotherapy:</strong> Allergy shots, or <a href="https://theconversation.com/hay-fever-how-immunotherapy-can-help-sufferers-not-getting-relief-from-the-usual-treatments-204945">immunotherapy</a>, can reduce hay fever symptoms by desensitising your immune system to allergens over time, providing long-lasting relief. Immunotherapy needs to be done several times before it’s effective. </p></li>
</ol>
<p>Making even just a few of these lifestyle adjustments can make a big difference in supporting your immune system and reducing your risk of getting sick or suffering hay fever symptoms during the colder months.</p><img src="https://counter.theconversation.com/content/216559/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>The authors do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Knowing what’s causing your symptoms is important for choosing the right treatment.Samuel J. White, Senior Lecturer in Genetic Immunology, Nottingham Trent UniversityPhilippe B. Wilson, Professor of One Health, Nottingham Trent UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/2019022023-03-24T15:49:30Z2023-03-24T15:49:30ZCould the common cold give children immunity against COVID? Our research offers clues<figure><img src="https://images.theconversation.com/files/516450/original/file-20230320-2149-tvxyat.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C5399%2C3892&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/kids-playing-cheerful-park-outdoors-concept-419185651">Rawpixel.com/Shuttersock</a></span></figcaption></figure><p>Why children are less likely to become severely ill with COVID compared with adults is not clear. Some have suggested that it might be because children are less likely to <a href="https://www.sciencedirect.com/science/article/pii/S2666379122000659">have diseases</a>, such as type 2 diabetes and high blood pressure, that are known to be linked to more severe COVID. Others have suggested that it could be because of a difference in <a href="https://www.sciencedirect.com/science/article/pii/S1521661620307488?via%3Dihub">ACE2 receptors</a> in children – ACE2 receptors being the route through which the virus enters our cells.</p>
<p>Some scientists have also suggested that children may have a higher level of existing immunity to COVID compared with adults. In particular, this immunity is thought to come from <a href="https://www.nature.com/articles/s41577-022-00809-x">memory T cells</a> (immune cells that help your body remember invading germs and destroy them) generated by common colds – some of which are caused by coronaviruses.</p>
<p>We put this theory to the test in a <a href="https://www.pnas.org/doi/10.1073/pnas.2220320120">recent study</a>. We found that T cells previously activated by a coronavirus that causes the common cold recognise SARS-CoV-2 (the virus that causes COVID) in children. And these responses declined with age.</p>
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<strong>
Read more:
<a href="https://theconversation.com/does-covid-really-damage-your-immune-system-and-make-you-more-vulnerable-to-infections-the-evidence-is-lacking-197253">Does COVID really damage your immune system and make you more vulnerable to infections? The evidence is lacking</a>
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<p>Early in the pandemic, scientists observed the presence of memory T cells able to recognise SARS-CoV-2 in people who had never been exposed to the virus. Such cells are often called cross-reactive T cells, as they stem from past infections due to pathogens other than SARS-CoV-2. Research has suggested these cells may provide some <a href="https://www.nature.com/articles/s41577-022-00809-x">protection against COVID</a>, and even enhance responses to COVID vaccines.</p>
<h2>What we did</h2>
<p>We used blood samples from children, sampled at age two and then again at age six, before the pandemic. We also included adults, none of whom had previously been infected with SARS-CoV-2.</p>
<p>In these blood samples, we looked for T cells specific to one of the coronaviruses that causes the common cold (called OC43) and for T cells that reacted against SARS-CoV-2.</p>
<p>We used an advanced technique called <a href="https://www.frontiersin.org/articles/10.3389/fimmu.2019.01515/full">high-dimensional flow cytometry</a>, which enabled us to identify T cells and characterise their state in significant detail. In particular, we looked at T cells’ reactivity against OC43 and SARS-CoV-2.</p>
<p>We found SARS-CoV-2 cross-reactive T cells were closely linked to the frequency of OC43-specific memory T cells, which was higher in children than in adults. The cross-reactive T cell response was evident in two-year-olds, strongest at age six, and then subsequently became weaker with advancing age. </p>
<p>We don’t know for sure if the presence of these T cells translates to <a href="https://www.nature.com/articles/s41577-022-00809-x">protection against COVID</a>, or how much. But this existing immunity, which appears to be especially potent in early life, could go some way to explaining why children tend to fare better than adults with a COVID infection.</p>
<figure class="align-center ">
<img alt="A little boy sleeps with a teddy bear." src="https://images.theconversation.com/files/516453/original/file-20230320-1833-16if7k.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/516453/original/file-20230320-1833-16if7k.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/516453/original/file-20230320-1833-16if7k.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/516453/original/file-20230320-1833-16if7k.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/516453/original/file-20230320-1833-16if7k.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/516453/original/file-20230320-1833-16if7k.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/516453/original/file-20230320-1833-16if7k.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Children are less likely to get very sick from COVID than adults.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/photo-baby-boy-sleeping-together-teddy-1507922393">Dragana Gordic/Shutterstock</a></span>
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<h2>Some limitations</h2>
<p>Our study is based on samples from adults (26-83 years old) and children at age two and six. We didn’t analyse samples from children of other ages, which will be important to further understand age differences, especially considering that the mortality rate from COVID in children is lowest from ages five to nine, and <a href="https://www.nature.com/articles/s41586-020-2918-0">higher in younger children</a>. We also didn’t have samples from teenagers or adults younger than 26. </p>
<p>In addition, our study investigated T cells circulating in the blood. But immune cells are also found in other parts of the body. It remains to be determined whether the age differences we observed in our study would be similar in samples from the <a href="https://www.nature.com/articles/s41590-022-01292-1">lower respiratory tract</a> or <a href="https://www.science.org/doi/10.1126/sciimmunol.abk0894">tonsil tissue</a>, for example, in which T cells reactive against SARS-CoV-2 have also been detected in adults who haven’t been exposed to the virus.</p>
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<strong>
Read more:
<a href="https://theconversation.com/colds-flu-and-covid-how-diet-and-lifestyle-can-boost-your-immune-system-197151">Colds, flu and COVID: how diet and lifestyle can boost your immune system</a>
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</em>
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<p>Nonetheless, this study provides new insights into T cells in the context of COVID in children and adults. Advancing our understanding of memory T cell development and maturation could help guide future vaccines and therapies.</p><img src="https://counter.theconversation.com/content/201902/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Marion Humbert received funding from KI Foundation for Virus Research (Karolinsk Institutet, Sweden) and Läkare mot AIDS (Sweden).</span></em></p><p class="fine-print"><em><span>Annika Karlsson receives funding from the Swedish Research Council (Dnr 2020-02033), CIMED project grant, senior (Dnr: 20190495), and Karolinska Institutet (Dnr: 2019-00931 and 2020-01599). </span></em></p>Certain immune cells acquired from a coronavirus that causes the common cold appear to react to COVID – but more so in children that adults.Marion Humbert, Postdoctoral Researcher in Immunology, Karolinska InstitutetAnnika Karlsson, Researcher, Department of Laboratory Medicine, Karolinska InstitutetLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1977152023-01-20T16:09:47Z2023-01-20T16:09:47ZHow the ‘tripledemic’ is restricting cold and flu medicine supplies – and what to do if you’re affected<figure><img src="https://images.theconversation.com/files/505365/original/file-20230119-24-qk0mcn.jpg?ixlib=rb-1.1.0&rect=23%2C11%2C7964%2C4479&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The UK, Canada and the US are all reportedly experiencing shortages of over-the-counter cold and flu medications.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-illustration/3d-rendering-empty-store-shelves-shortage-1830813587">Mircea Maties/ Shutterstock</a></span></figcaption></figure><p>This winter has been <a href="https://theconversation.com/nhs-crisis-underlying-problems-are-starting-to-be-addressed-197358">one of the worst on record</a> for the NHS. Ambulance and A&E waiting times are at all-time highs, and many are struggling to access emergency treatment. </p>
<p>Patients are now reporting difficulties accessing certain over-the-counter medicines used to treat colds and flu from <a href="https://www.thetimes.co.uk/article/uk-cold-flu-medicine-shortage-pharmacy-january-2023-g70mz2dn5">pharmacies and high-street outlets</a>. While medicine shortages have been a <a href="https://theconversation.com/heres-why-so-many-medications-are-out-of-stock-and-what-to-do-if-it-affects-you-190476">common phenomenon</a> in previous years, they have often been the result of supply chain issues due to global events, such as the pandemic or the Russian invasion of Ukraine. But these aren’t the same reasons people are reporting when experiencing shortages of non-prescription, over-the-counter products.</p>
<h2>‘Tripledemic’</h2>
<p>Several countries, including <a href="https://www.express.co.uk/news/science/1717579/nhs-excess-deaths-christmas-covid-flu-tripledemic">the UK</a>, the <a href="https://www.today.com/health/tripledemic-winter-2022-states-hit-hardest-rcna55983">US</a> and <a href="https://www.wsws.org/en/articles/2022/12/22/zobm-d22.html">Canada</a>, are reportedly in the midst of a “tripledemic” this winter — meaning they’re experiencing higher than expected cases of <a href="https://www.ons.gov.uk/peoplepopulationandcommunity/healthandsocialcare/conditionsanddiseases/articles/coronaviruscovid19latestinsights/infections">COVID</a>, flu and <a href="https://theconversation.com/rsv-faq-what-is-rsv-who-is-at-risk-when-should-i-seek-emergency-care-for-my-child-195292">RSV</a> concurrently. </p>
<p>In England alone, it’s estimated that <a href="https://www.ons.gov.uk/peoplepopulationandcommunity/healthandsocialcare/conditionsanddiseases/articles/coronaviruscovid19latestinsights/infections">one in 25 people</a> are currently infected with COVID. Flu cases are also on the rise, with hospital admissions at their highest level since the <a href="https://www.express.co.uk/news/uk/1717684/flu-season-winter-hospital-admissions-doctors-medical-advice-face-masks-deaths-ont">winter of 2017-18</a>. Alongside this, there have also been outbreaks of <a href="https://theconversation.com/strep-a-three-doctors-explain-what-you-need-to-look-out-for-195972">strep A</a> and seasonal illnesses. </p>
<p>Since these viral infections cause symptoms such as fever, coughs and sore throats, many people turn to over-the-counter medicines to remedy them. Some may also be making anticipatory purchases in case of illness. </p>
<p>In Canada, pharmacists have reported bare shelves, with a lack of both children’s and adults’ cold and flu medication. Worries about shortages can then lead to <a href="https://globalnews.ca/news/9394274/cold-flu-medication-canada-drug-shortage-pharmacists/">stockpiling and panic buying</a>. In the US, <a href="https://www.healthline.com/health-news/theres-a-shortage-of-cold-and-flu-meds-for-kids-what-parents-can-do#Flu-medications-in-demand">some pharmacies</a> have opted to restrict sales due to increased demand by putting a cap on the number of certain medications people can <a href="https://edition.cnn.com/2022/12/28/health/flu-covid-rsv-medications-tests/index.html">purchase at a time</a>.</p>
<p>In the UK, popular pain and fever products reportedly have <a href="https://www.express.co.uk/news/uk/1718664/calpol-uk-shortage-medicine-pharmacy-nhs-antibiotics">low stock availability</a>, and there are also <a href="https://www.express.co.uk/news/science/1717113/uk-cough-medicine-shortage-john-cleese-nhs-pharmacies">shortages of cough mixtures and lozenges</a>.</p>
<h2>Not enough stock?</h2>
<p>Manufacturers in the UK have said that <a href="https://www.dailymail.co.uk/news/article-11594553/Pharmacists-running-low-supplies-cold-flu-medicines-amid-huge-demand.html">stock does exist</a> and they are working to respond to higher-than-usual demand. In Canada, pharmacies are receiving supplies, but stock sells out almost as <a href="https://beta.ctvnews.ca/national/health/2023/1/10/1_6224500.amp.html">soon as it hits the shelves</a>. Many people are finding it difficult to get the medicines they need – with some places out of stock entirely.</p>
<p>Some think <a href="https://www.bbc.co.uk/news/health-64168959">inadequate government planning</a> may explain the <a href="https://www.theguardian.com/society/2023/jan/04/shortage-of-cough-and-cold-medicines-in-uk-is-governments-fault-say-pharmacists">lack of stock</a> in the UK. But again, there’s no clear evidence for this. </p>
<p>An earlier start to seasonal flu has caused problems in Canada, with manufacturers not having time to <a href="https://beta.ctvnews.ca/national/health/2023/1/10/1_6224500.amp.html">build up essential stocks in summer</a> and an uptick in seasonal illness creating higher product demand. In early January 2023, the Canadian government announced it was aware of <a href="https://www.ctvnews.ca/health/health-canada-confirms-shortage-of-adult-cold-and-flu-medicine-1.6220662">supply constraints</a> of products used to treat cold and flu symptoms. Likewise, the UK government confirmed it had been made aware of <a href="https://www.independent.co.uk/news/uk/hrt-pharmacies-government-superdrug-department-of-health-and-social-care-b2255848.html?r=64644">availabilty issues</a> of some branded cold and flu medicines.</p>
<figure class="align-center ">
<img alt="A photo of an empty pharmacy shelf, with a sign indicating supply chain issues have fuelled shortages of cold and flu medicines." src="https://images.theconversation.com/files/505367/original/file-20230119-26-z5qkuc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/505367/original/file-20230119-26-z5qkuc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/505367/original/file-20230119-26-z5qkuc.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/505367/original/file-20230119-26-z5qkuc.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/505367/original/file-20230119-26-z5qkuc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/505367/original/file-20230119-26-z5qkuc.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/505367/original/file-20230119-26-z5qkuc.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Supply chain issues may be one reason for shortages in certain countries.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/edmonton-canada-december-5-2022-sign-2239275375">Jenari/ Shutterstock</a></span>
</figcaption>
</figure>
<p>There’s also a chance that stock isn’t being distributed evenly. Some pharmacies may carry more stock than others, and could help support areas with low stock availability. Pharmacies with multiple sites <a href="https://www.dailymail.co.uk/news/article-11594553/Pharmacists-running-low-supplies-cold-flu-medicines-amid-huge-demand.html">will know stock levels held in their stores</a> and can move stock between locations. The UK government has said that availability issues with some branded cold and flu medicines are <a href="https://www.independent.co.uk/news/uk/hrt-pharmacies-government-superdrug-department-of-health-and-social-care-b2255848.html">temporary and localised</a>, and that it is working with suppliers to investigate these. </p>
<p>Another problem that may be feeding into supply issues is the forecasting used to inform stock production. If stock forecasting for winter 2022-23 was based on previous years’ usage figures, it may be skewed. During the pandemic, <a href="https://www.reuters.com/world/europe/pandemic-curbs-linked-early-start-europes-winter-flu-season-2022-12-30/">many preventative measures</a> (such as wearing masks) protected us against common germs and viruses too, lowering levels of illness and <a href="https://www.ctvnews.ca/health/health-canada-confirms-shortage-of-adult-cold-and-flu-medicine-1.6220662">reducing demand for cold and flu remedies</a>. In light of this, manufacturing quantities may have been adjusted to avoid stock wastage, not knowing that an earlier surge of seasonal illness would happen this year. </p>
<h2>What you can do</h2>
<p>If you have cold or flu symptoms, you should seek advice about treatment from your pharmacist and, as needed, your doctor or healthcare provider. </p>
<p>If you’re finding it difficult to get your usual over-the-counter products for cold and flu, you may want to try alternatives – including generic (non-branded) products. For instance, if you’re <a href="https://www.dailymail.co.uk/news/article-11592247/Lemsip-shortage-hits-Britain-shoppers-say-cold-flu-medicines-shelves.html">having trouble finding products such as Lemsip</a> to manage cold and flu symptoms, paracetamol and vitamin C are great alternatives as these are often the main ingredients in cold and flu products. The same is true of throat lozenges, with many alternatives on offer. </p>
<p>If one formulation of a product isn’t available, your pharmacist may be able to recommend an alternative form – such as substituting children’s Calpol syrup with Calpol tablets which dissolve in the mouth (where age appropriate). </p>
<p>COVID and flu vaccines are still recommended to prevent serious viruses, so people are encouraged to get these as soon as they can. While the optimal time to book your <a href="https://www.nhs.uk/conditions/vaccinations/flu-influenza-vaccine/">flu jab is in the autumn or early winter</a>, before flu starts spreading, it will still offer protection if you get it now.</p>
<p>The UK Health Security Agency is warning that winter illnesses including flu, COVID, RSV and strep A <a href="https://www.thetimes.co.uk/article/uk-cold-flu-medicine-shortage-pharmacy-january-2023-g70mz2dn5">are circulating at high levels</a> with no immediate sign of abatement. If you’re one of the millions of people currently suffering from one of these illnesses, speak to your pharmacist to know what treatment options are available to you.</p>
<p>Medicine shortages have occurred in the UK for many years – and will continue to do so. But the current shortage of cold and flu products shows an escalation of issues with the UK’s medicine supply chains, making it clear that weakness in the system needs to be urgently addressed.</p><img src="https://counter.theconversation.com/content/197715/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>The authors do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>A combination of high demand and poor stock planning may explain current problems.Liz Breen, Director of the Digital Health Enterprise Zone (DHEZ), University of Bradford, Professor in Health Service Operations, University of BradfordZoe Edwards, Practice Pharmacist/Honorary Senior Research Fellow, University of BradfordLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1918222022-11-09T13:06:11Z2022-11-09T13:06:11ZCOVID, flu, RSV – how this triple threat of respiratory viruses could collide this winter<figure><img src="https://images.theconversation.com/files/493927/original/file-20221107-3517-a6vy2o.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C8192%2C5464&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/unhealthy-little-boy-child-measure-high-2099010130">Dragana Gordic/Shutterstock</a></span></figcaption></figure><p>As the days get shorter and the weather colder in the northern hemisphere, health officials <a href="https://www.theatlantic.com/health/archive/2022/10/covid-winter-wave-2022-predictions/671658/">have warned</a> of a perfect storm of infectious respiratory diseases over the winter months.</p>
<p>Outbreaks of seasonal diseases like influenza and respiratory syncytial virus (RSV) are already putting pressure on the overburdened NHS. If surges of these illnesses collide with another large COVID wave, we could be facing a <a href="https://www.heraldscotland.com/news/23083882.nhs-preparing-significant-excess-deaths-winter">public health disaster</a>. Some have called this threat a “<a href="https://www.thetimes.co.uk/article/tripledemic-threat-of-covid-flu-and-rsv-winter-infections-2cgh9bc95">tripledemic</a>”. </p>
<p>But how can we realistically expect the winter to play out? To try to answer this question, we can look at the recent and current trends of some of the most common winter infections in the UK.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/omicron-bq-1-and-bq-1-1-an-expert-answers-three-key-questions-about-these-new-covid-variants-192873">Omicron BQ.1 and BQ.1.1 – an expert answers three key questions about these new COVID variants</a>
</strong>
</em>
</p>
<hr>
<h2>1. COVID-19</h2>
<p>Let’s start with the most obvious one, SARS-CoV-2 (the virus that causes COVID-19). The UK has so far been through <a href="https://www.nature.com/articles/d41586-022-03157-x">multiple COVID waves</a>, fuelled by a combination of behavioural changes, emerging variants and waning immunity.</p>
<figure class="align-center ">
<img alt="A graph showing the number of COVID cases and PCR positivity rate in the UK up to October 30, 2022." src="https://images.theconversation.com/files/494413/original/file-20221109-26-gkiink.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/494413/original/file-20221109-26-gkiink.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=531&fit=crop&dpr=1 600w, https://images.theconversation.com/files/494413/original/file-20221109-26-gkiink.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=531&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/494413/original/file-20221109-26-gkiink.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=531&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/494413/original/file-20221109-26-gkiink.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=667&fit=crop&dpr=1 754w, https://images.theconversation.com/files/494413/original/file-20221109-26-gkiink.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=667&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/494413/original/file-20221109-26-gkiink.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=667&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The trajectory of COVID cases in England over the past year.</span>
<span class="attribution"><a class="source" href="https://www.gov.uk/government/statistics/national-flu-and-covid-19-surveillance-reports-2022-to-2023-season">Adam Kleczkowski/UKHSA</a>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>In contrast to the large epidemic last winter, more recent waves have been <a href="https://www.thinkglobalhealth.org/article/it-end-covid-19-we-know-it">relatively small</a>. And despite <a href="https://www.mirror.co.uk/news/uk-news/breaking-covid-deaths-surge-40-28266450">initial concerns</a> about a significant winter surge this year, the number of COVID cases <a href="https://www.gov.uk/government/news/national-flu-and-covid-19-surveillance-reports-published">is currently decreasing</a>. But the pandemic isn’t over yet, and what will happen next is <a href="https://www.nature.com/articles/d41586-022-03445-6">highly uncertain</a>.</p>
<p>So far, there’s <a href="https://www.weforum.org/agenda/2020/07/does-covid-19-thrive-in-cold-weather/">mixed evidence</a> as to whether COVID is worse in cold weather. But during winter, people tend to stay indoors more and reduce ventilation, giving viruses more opportunity to spread.</p>
<p>In an <a href="https://www.nature.com/articles/d41586-022-03157-x">optimistic scenario</a>, small-scale outbreaks might continue into the winter as COVID becomes “<a href="https://www.mckinsey.com/industries/healthcare-systems-and-services/our-insights/when-will-the-covid-19-pandemic-end">endemic</a>”.</p>
<p>Previous COVID waves have largely been driven by single dominant variants – alpha and delta in 2020-21 and omicron in 2021-22. This time, the many “descendants” of omicron are <a href="https://public.tableau.com/app/profile/raj.rajnarayanan/viz/USAVariantDB/VariantDashboard">multiplying worldwide</a>, and the current spread is instead caused by a <a href="https://fortune.com/well/2022/10/15/covid-omicron-split-multiple-variants-peaking-different-countries-same-time-scenarios-fall-winter-pandemic-epiidemic-endemic-xbb/">mixture of variants</a> peaking in different countries at different times. </p>
<p>But it is possible that if a highly transmissible variant <a href="https://www.nationalworld.com/health/covid-what-will-coronavirus-be-like-during-winter-further-waves-variants-and-immunity-explained-by-expert-3889094">emerges</a> this winter, it might cause <a href="https://www.science.org/content/article/big-covid-19-waves-may-be-coming-new-omicron-strains-suggest">another large wave</a> of infections.</p>
<h2>2. Influenza</h2>
<p>Seasonal influenza is a respiratory infection caused by <a href="https://www.who.int/en/news-room/fact-sheets/detail/influenza-(seasonal)">four types of viruses</a>, two of which (A and B) are common and can cause severe illness, hospitalisation and death, particularly in vulnerable people. </p>
<p>Flu is highly <a href="https://sitn.hms.harvard.edu/flash/2014/the-reason-for-the-season-why-flu-strikes-in-winter/">seasonal</a> in <a href="https://en.wikipedia.org/wiki/Temperate_climate">climates</a> like in the UK, partly because people spend <a href="https://www.popsci.com/science/article/2013-01/fyi-why-winter-flu-season/">more time indoors</a>. The virus itself also <a href="https://journals.plos.org/plospathogens/article?id=10.1371/journal.ppat.0030151">appears to favour</a> low temperatures and low humidity. </p>
<p>Not unlike COVID, factors including waning immunity and the <a href="https://www.nature.com/articles/nrmicro.2017.118">evolution of influenza viruses</a> also drive repeated outbreaks.</p>
<figure class="align-center ">
<img alt="A graph showing the number of flu cases and weekly positivity rate in England over recent years." src="https://images.theconversation.com/files/494412/original/file-20221109-14-7emtoa.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/494412/original/file-20221109-14-7emtoa.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=477&fit=crop&dpr=1 600w, https://images.theconversation.com/files/494412/original/file-20221109-14-7emtoa.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=477&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/494412/original/file-20221109-14-7emtoa.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=477&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/494412/original/file-20221109-14-7emtoa.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=599&fit=crop&dpr=1 754w, https://images.theconversation.com/files/494412/original/file-20221109-14-7emtoa.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=599&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/494412/original/file-20221109-14-7emtoa.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=599&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Influenza infections in England over recent years, compared with the current season.</span>
<span class="attribution"><a class="source" href="https://www.gov.uk/government/statistics/national-flu-and-covid-19-surveillance-reports-2022-to-2023-season">Adam Kleczkowski/UKHSA</a>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Flu seasons usually start in November, with cases peaking from December to March. In some years, the outbreaks are particularly severe, as <a href="https://www.theguardian.com/society/2018/jan/18/flu-outbreak-gps-under-huge-pressure-as-deaths-soar-to-120">in the UK in 2018</a>. </p>
<p>Flu responded the same way COVID did to non-pharmaceutical interventions, including lockdown restrictions and mask-wearing. The number of cases in the 2020-21 winter was <a href="https://www.dailymail.co.uk/news/article-9206071/Flu-wiped-lowest-level-130-YEARS-seasonal-virus-plummets-95.html">very low</a>. It came back the following season later in the year, but was still limited.</p>
<p>There is <a href="https://www.medrxiv.org/content/10.1101/2022.10.02.22280610v2">concern</a> that the long period during which our bodies were not exposed to the flu might have created an “immunity gap” making us particularly vulnerable this year. </p>
<p>Australia saw the worst <a href="https://theconversation.com/flu-is-set-for-a-big-comeback-now-covid-restrictions-are-lifted-heres-what-you-need-to-know-191520">seasonal flu outbreak</a> in five years during its recent winter, coinciding with a large COVID surge. While it’s still early to see what the 2022-23 winter will bring in the northern hemisphere, the current <a href="https://www.bbc.co.uk/news/health-63427651">outbreak</a> in England is early and large compared with pre-pandemic years.</p>
<h2>3. RSV</h2>
<p>RSV is <a href="https://www.cdc.gov/rsv/index.html">a common winter virus</a> which usually causes mild coughs and colds but occasionally results in serious infections like <a href="https://www.nhs.uk/conditions/bronchiolitis/">bronchiolitis</a> and <a href="https://www.nhs.uk/conditions/pneumonia/">pneumonia</a>, particularly in <a href="https://ukhsa.blog.gov.uk/2022/10/25/5-ways-to-protect-your-under-5s-this-winter/">young children</a>. </p>
<figure class="align-center ">
<img alt="A graph showing RSV hospitalisations in England over recent years." src="https://images.theconversation.com/files/494431/original/file-20221109-15-fmi2ww.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/494431/original/file-20221109-15-fmi2ww.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=477&fit=crop&dpr=1 600w, https://images.theconversation.com/files/494431/original/file-20221109-15-fmi2ww.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=477&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/494431/original/file-20221109-15-fmi2ww.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=477&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/494431/original/file-20221109-15-fmi2ww.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=600&fit=crop&dpr=1 754w, https://images.theconversation.com/files/494431/original/file-20221109-15-fmi2ww.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=600&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/494431/original/file-20221109-15-fmi2ww.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=600&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Weekly hospital admissions for RSV in England over recent years, compared with the current season.</span>
<span class="attribution"><a class="source" href="https://www.gov.uk/government/statistics/national-flu-and-covid-19-surveillance-reports-2022-to-2023-season">Adam Kleczkowski/UKHSA</a>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>In pre-pandemic years it followed a seasonal pattern, with most cases occurring in early winter. After a hiatus in 2020-21, many cases were registered out of season in the summer of 2021. This unusual pattern is again suspected to result from a <a href="https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(22)00544-8/fulltext">loss of immunity</a>. </p>
<p>The seasonal pattern seems to be returning, but this autumn has already seen <a href="https://www.thesun.co.uk/health/20314474/urgent-warning-soaring-number-kids-hospital-killer-virus/">high hospitalisation numbers</a>.</p>
<h2>4. Common cold viruses</h2>
<p>Common colds are caused by a variety of pathogens, including <a href="https://www.cdc.gov/features/rhinoviruses/index.html">rhinoviruses</a>, <a href="https://www.cdc.gov/dotw/enteroviruses/">enteroviruses</a>, and <a href="https://www.cdc.gov/coronavirus/general-information.html">other coronaviruses</a>. </p>
<p>Like flu, the onset of the more benign coronaviruses generally occurs in November, with the peak between January and March. Rhinoviruses and enteroviruses tend to peak in autumn rather than in winter. </p>
<figure class="align-center ">
<img alt="A graph showing the number of rhinovirus cases and weekly positivity rate in England over recent years." src="https://images.theconversation.com/files/494415/original/file-20221109-2908-8z0pn6.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/494415/original/file-20221109-2908-8z0pn6.png?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=477&fit=crop&dpr=1 600w, https://images.theconversation.com/files/494415/original/file-20221109-2908-8z0pn6.png?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=477&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/494415/original/file-20221109-2908-8z0pn6.png?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=477&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/494415/original/file-20221109-2908-8z0pn6.png?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=599&fit=crop&dpr=1 754w, https://images.theconversation.com/files/494415/original/file-20221109-2908-8z0pn6.png?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=599&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/494415/original/file-20221109-2908-8z0pn6.png?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=599&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Rhinovirus infections in England over recent years, compared with the current season.</span>
<span class="attribution"><a class="source" href="https://www.gov.uk/government/statistics/national-flu-and-covid-19-surveillance-reports-2022-to-2023-season">Adam Kleczkowski/UKHSA</a>, <span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>The 2021-22 rhinovirus season was similar to pre-pandemic trends, but we’re seeing higher numbers so far this year. The infection is usually mild, and most people quickly recover, but severe cases in vulnerable people <a href="https://nypost.com/2022/09/19/covid-lockdown-blamed-for-increase-in-severe-common-cold-in-kids/">can add</a> to the pressure on hospitals.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/summer-colds-this-may-explain-why-so-many-have-suffered-them-this-year-188932">Summer colds: this may explain why so many have suffered them this year</a>
</strong>
</em>
</p>
<hr>
<h2>Protecting ourselves</h2>
<p>This winter, the UK will probably face high pressure from respiratory viruses. Cases of seasonal diseases are possibly higher due to the lack of exposure <a href="https://alasdairmunro.substack.com/p/why-are-all-the-kids-sick-in-summer">during the lockdowns</a>. In addition, some research suggests COVID infections might <a href="https://www.sciencedaily.com/releases/2021/10/211028125803.htm">affect people’s immunity</a>, putting them at higher risk of infection with other viruses. </p>
<p>To <a href="https://www.youtube.com/watch?v=ou88Iei-52k">reduce the spread</a> of respiratory viruses, we can continue with measures like <a href="https://www.ncbi.nlm.nih.gov/books/NBK143278/">ventilation</a>, mask-wearing and hand-washing. </p>
<p>We can also strengthen our immune systems, for example with <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8220366/">proper nutrition</a> and <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7387807/">exercise</a>. </p>
<p>And although we don’t have vaccines available for RSV or common cold viruses, COVID and flu vaccines are an important tool to prevent severe illness this winter.</p><img src="https://counter.theconversation.com/content/191822/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Adam Kleczkowski receives funding from the UKRI and the Scottish Government.</span></em></p>Cases of seasonal diseases may be higher due to a lack of exposure during the pandemic. Here are four graphs which give us some clues as to how things might play out.Adam Kleczkowski, Professor of Mathematics and Statistics, University of Strathclyde Licensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1904292022-09-29T20:05:08Z2022-09-29T20:05:08ZWhy has my cold dragged on so long? And how do I know when it’s morphed into something more serious?<figure><img src="https://images.theconversation.com/files/483890/original/file-20220912-7256-6grcdr.jpg?ixlib=rb-1.1.0&rect=0%2C9%2C6120%2C4076&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.pexels.com/photo/woman-lying-on-bed-while-blowing-her-nose-3807629/">Photo by Andrea Piacquadio/Pexels</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span></figcaption></figure><p>Common colds are caused by viruses. There are no effective cures, and antibiotics do not work on viruses, so treatment is targeted at managing the symptoms until your immune system has cleared the cold.</p>
<p>So why might someone go to a doctor at all for a cold?</p>
<p>Well, occasionally a cold might turn into something more serious requiring assessment and specific treatment, and a GP visit could be warranted. Or you may just want reassurance and advice.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/sore-throats-suck-do-throat-lozenges-help-at-all-184454">Sore throats suck. Do throat lozenges help at all?</a>
</strong>
</em>
</p>
<hr>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/483887/original/file-20220912-54657-jcnlj0.jpg?ixlib=rb-1.1.0&rect=0%2C50%2C6709%2C4416&q=45&auto=format&w=1000&fit=clip"><img alt="A woman blows her nose." src="https://images.theconversation.com/files/483887/original/file-20220912-54657-jcnlj0.jpg?ixlib=rb-1.1.0&rect=0%2C50%2C6709%2C4416&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/483887/original/file-20220912-54657-jcnlj0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/483887/original/file-20220912-54657-jcnlj0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/483887/original/file-20220912-54657-jcnlj0.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/483887/original/file-20220912-54657-jcnlj0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/483887/original/file-20220912-54657-jcnlj0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/483887/original/file-20220912-54657-jcnlj0.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Occasionally a cold might turn into something more serious requiring assessment and specific treatment.</span>
<span class="attribution"><a class="source" href="https://www.pexels.com/photo/woman-blowing-nose-7195040/">Photo by Karolina Grabowska/Pexels</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<h2>Don’t rush to the GP for something totally normal</h2>
<p>Problems arise when there too many unwarranted visits to GPs for cold symptoms.</p>
<p>Studies have shown <a href="https://www.annfammed.org/content/11/1/5">antibiotics</a> are <a href="https://onlinelibrary.wiley.com/doi/abs/10.5694/mja16.01042">still prescribed widely</a> for viral colds, even though they don’t help, and this contributes to antibiotic resistance. It hastens the arrival of an era when many antibiotics simply don’t work at all.</p>
<p>On average, children have <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7152362/">four to six colds</a> per year, while in adults the average is <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7152362/">two to three</a>.</p>
<p>Some people are more <a href="https://www.sciencedirect.com/science/article/abs/pii/S1530156705601189?via%3Dihub">prone</a> to colds, but we don’t know exactly why.</p>
<p>The usual cold persists about one week, although 25% last two weeks. In one <a href="https://journals.asm.org/doi/10.1128/jcm.35.11.2864-2868.1997">study</a> with 346 adults, the infection lasted 9.5 to 11 days. </p>
<p>Cold symptoms may last longer in younger children. One <a href="https://publications.aap.org/pediatrics/article-abstract/87/2/129/56810/Upper-Respiratory-Tract-Infections-in-Young?redirectedFrom=fulltext">study</a> showed an average duration of colds ranged from 6.6 to 9 days. But symptoms lasted more than 15 days in 6.5% of 1-3 year old children in home care, and 13.1% of 2-3 year old children in day care.</p>
<p>A cough tends to last longer than other symptoms, and often beyond the actual viral infection. The average <a href="https://www.annfammed.org/content/11/1/5">duration</a> of a cough is about 17.8 days.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/483889/original/file-20220912-54657-4uy5r1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A man coughs into his elbow." src="https://images.theconversation.com/files/483889/original/file-20220912-54657-4uy5r1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/483889/original/file-20220912-54657-4uy5r1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/483889/original/file-20220912-54657-4uy5r1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/483889/original/file-20220912-54657-4uy5r1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/483889/original/file-20220912-54657-4uy5r1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/483889/original/file-20220912-54657-4uy5r1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/483889/original/file-20220912-54657-4uy5r1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A cough tends to last longer than other symptoms.</span>
<span class="attribution"><a class="source" href="https://www.pexels.com/photo/a-sick-man-covering-his-mouth-4031634/">Photo by Edward Jenner/Pexels</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<h2>Discoloured sputum, cough or snot</h2>
<p>Discoloured mucus in snot or cough is a common trigger for requesting antibiotics from a GP. But as we know, antibiotics are useless against a virus. They only work against bacterial infection. </p>
<p>In fact, thick or coloured nasal mucus secretion is common following colds. Only a tiny proportion <a href="https://europepmc.org/article/pmc/pmc7151789">involve</a> bacterial infection.</p>
<p>When it happens, this is termed <a href="https://www.nps.org.au/australian-prescriber/articles/treating-acute-sinusitis-3">acute rhinosinusitis</a>. But antibiotics are not recommended unless it lasts more than ten to 14 days and there are <a href="https://europepmc.org/article/pmc/pmc7151789">signs</a> of bacterial sinusitis infection, such as:</p>
<ul>
<li>symptoms worsening after improvement in the original cold</li>
<li>return of fever and</li>
<li>strong facial pain.</li>
</ul>
<p>A prolonged cough after colds is usually caused by an irritated throat or the clearing of sticky mucus coming down from the nose. The cough may sound moist (so wrongly called “chesty”) due to the phlegm, but only small amounts of phlegm are coughed up. </p>
<p>Yellow or green coloured mucus is often interpreted as a <a href="http://theconversation.com/health-check-what-you-need-to-know-about-mucus-and-phlegm-33192">sign</a> of bacterial infection.</p>
<p>But yellow or green sputum alone <a href="https://www.tandfonline.com/doi/full/10.1080/02813430902759663">does not</a> mean you have a serious bacterial infection. One study found being prescribed antibiotics under these circumstances <a href="https://erj.ersjournals.com/content/38/1/119">failed</a> to shorten recovery time. </p>
<p>Nasal saline sprays and washes can be used to rinse out the nose and sinuses and possibly <a href="https://dtb.bmj.com/content/57/4/56">shorten</a> rhinosinusitis and cough after colds.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/483891/original/file-20220912-68568-ej88qo.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/483891/original/file-20220912-68568-ej88qo.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/483891/original/file-20220912-68568-ej88qo.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=429&fit=crop&dpr=1 600w, https://images.theconversation.com/files/483891/original/file-20220912-68568-ej88qo.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=429&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/483891/original/file-20220912-68568-ej88qo.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=429&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/483891/original/file-20220912-68568-ej88qo.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=539&fit=crop&dpr=1 754w, https://images.theconversation.com/files/483891/original/file-20220912-68568-ej88qo.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=539&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/483891/original/file-20220912-68568-ej88qo.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=539&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">A cold can make you feel rubbish for quite a while.</span>
<span class="attribution"><a class="source" href="https://www.pexels.com/photo/apartment-bed-carpet-chair-269141/">Photo by Pixabay, via Pexels</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<h2>Could it just be hayfever, or another underlying issue?</h2>
<p>Hayfever or allergic rhinitis is a common cause for prolonged symptoms after a cold, especially cough and nasal congestion and maybe also sneezing. </p>
<p>The damage in the upper airways following a viral infection may allow airborne allergens to trigger hayfever. Self-medicating with antihistamines, nasal saline spray or intranasal steroids is worthwhile if <a href="https://theconversation.com/health-check-why-do-i-have-a-cough-and-what-can-i-do-about-it-119172">allergic rhinitis</a> is suspected. </p>
<p>There may be other reasons for persistence of cough, such as exacerbation of underlying asthma or chronic lung disease. If so, this may require a visit to your GP.</p>
<h2>What about bronchitis or pneumonia?</h2>
<p>Many people worry about developing a chest infection after a cold. </p>
<p>Acute bronchitis is a self-limiting infectious disease characterised by acute cough with or without sputum but without <a href="https://www.nhs.uk/conditions/pneumonia/">signs of pneumonia</a> (such as high temperatures and feeling breathless). Most acute bronchitis cases are caused by viruses. Antibiotics are often prescribed, but produce <a href="https://www.tandfonline.com/doi/full/10.1080/14787210.2016.1193435">no significant clinical improvement</a> compared with placebo, so are not recommended.</p>
<p>Pneumonia is a potentially serious secondary disease that <a href="https://pubmed.ncbi.nlm.nih.gov/28159155/">may follow</a> an episode of flu in a small number of cases, but is <a href="https://www.ncbi.nlm.nih.gov/books/NBK532961/">relatively rare</a> following a cold. Symptoms and signs of pneumonia feature heavily in the list of warning signs that signal the need for a medical assessment. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/486977/original/file-20220928-12-fzoana.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="A man looks at his phone." src="https://images.theconversation.com/files/486977/original/file-20220928-12-fzoana.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/486977/original/file-20220928-12-fzoana.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/486977/original/file-20220928-12-fzoana.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/486977/original/file-20220928-12-fzoana.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/486977/original/file-20220928-12-fzoana.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/486977/original/file-20220928-12-fzoana.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/486977/original/file-20220928-12-fzoana.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=566&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Sometimes, contacting your GP is a good idea.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<h2>When should I seek medical help for a cough or a cold?</h2>
<p>Contact a GP if you experience:</p>
<ul>
<li>shortness of breath or trouble breathing</li>
<li>feeling faint or dizzy</li>
<li>chest pain</li>
<li>dehydration </li>
<li>fever or cough symptoms that improve but then return or worsen</li>
<li>worsening of chronic medical conditions such as asthma.</li>
</ul>
<p>This is not a complete list, but may guide you on what to expect and what to watch out for. </p>
<p>You might also contact your GP (perhaps for a telehealth consult) if you are finding your symptoms very unpleasant, or are concerned your condition is more serious or prolonged than expected. You might just need reassurance and education about self care options.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/forget-nose-spray-good-sex-clears-a-stuffy-nose-just-as-effectively-and-is-a-lot-more-fun-167901">Forget nose spray, good sex clears a stuffy nose just as effectively — and is a lot more fun</a>
</strong>
</em>
</p>
<hr>
<img src="https://counter.theconversation.com/content/190429/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>David King does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Problems arise when there are too many unwarranted visits to GPs for cold symptoms. Occasionally, though, a cold might turn into something that needs specific diagnosis and treatment.David King, Senior Lecturer in General Practice, The University of QueenslandLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1889322022-08-19T05:10:24Z2022-08-19T05:10:24ZSummer colds: this may explain why so many have suffered them this year<figure><img src="https://images.theconversation.com/files/479883/original/file-20220818-639-d99p6k.jpg?ixlib=rb-1.1.0&rect=51%2C8%2C5760%2C3819&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Enteroviruses and parainfluenza 3 virus are more common in summer.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/picture-beautiful-women-bikini-handkerchief-sick-676784800">Estrada Anton/ Shutterstock</a></span></figcaption></figure><p>Most of us associate colds and the flu with colder weather. But that doesn’t mean you can’t still catch a cold during the summer. Some viruses are even more common in summer than in the winter. </p>
<p>The flu virus and respiratory syncytial virus (RSV) are <a href="https://www.annualreviews.org/doi/10.1146/annurev-virology-012420-022445">more common in the winter months</a>, as the <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4097773/">colder temperatures</a> and more time spent indoors around other people provide them with favourable conditions to spread.</p>
<p>But in the summer, enteroviruses and parainfluenza 3 virus are <a href="https://www.annualreviews.org/doi/10.1146/annurev-virology-012420-022445">much more common</a>, with infections from these viruses tending to peak in <a href="http://dx.doi.org/10.15585/mmwr.mm6718a2">summer and early autumn</a> when the weather is <a href="https://link.springer.com/article/10.1007/s00705-013-1863-8">warmer</a> and <a href="https://www.sciencedirect.com/science/article/pii/S1386653216305509">more humid</a>.</p>
<p>Both viruses cause typical cold symptoms, including a runny nose, low energy, muscle aches, cough, headaches and sore throat. Parainfluenza can sometimes cause <a href="https://www.cdc.gov/parainfluenza/about/index.html">bronchitis and pneumonia</a> in people who have a poorly functioning immune system. While these symptoms are similar to allergies, the telltale difference is that <a href="https://www.mayoclinic.org/diseases-conditions/common-cold/expert-answers/common-cold/faq-20057857">allergies tend not to cause</a> fevers or body aches, and rarely cause coughs. Colds last from a few days to two weeks, but, depending on what triggered the allergy, allergy symptoms can last all summer for some people.</p>
<p>It seems counter-intuitive that certain viral infections are more common in warmer months when we spend more time outdoors. But in the warmer months, we also socialise and travel more – meaning we’re mixing with a greater number of people, sometimes from different parts of the world. Many of us also gravitate towards air-conditioned indoor environments when the weather is hot.</p>
<p>But the structure of a virus may also explain why some spread more easily in the warmer months.</p>
<p>For a virus to spread and infect healthy cells, it needs to survive both outside and inside the body – and it also needs to use the machinery of human cells (such as their DNA) to create copies of itself.</p>
<p>Viruses are surrounded by a protein “coat”, called a capsid, which not only gives the virus its shape but also protects the genetic material inside. The capsid also helps the virus attach to human cells to cause infections.</p>
<figure class="align-center ">
<img alt="A digital illustration of enteroviruses." src="https://images.theconversation.com/files/479884/original/file-20220818-1579-tnodgw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/479884/original/file-20220818-1579-tnodgw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/479884/original/file-20220818-1579-tnodgw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/479884/original/file-20220818-1579-tnodgw.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/479884/original/file-20220818-1579-tnodgw.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/479884/original/file-20220818-1579-tnodgw.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/479884/original/file-20220818-1579-tnodgw.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Enteroviruses don’t have an envelope.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-illustration/illustration-enterovirus-d68-which-causes-respiratory-346238837">Kateryna Kon/ Shutterstock</a></span>
</figcaption>
</figure>
<p>Some viruses (called “enveloped viruses”) are also surrounded by a lipid (fatty acid) envelope. This viral envelope helps the virus to avoid being destroyed by the immune system. It also plays a role in interacting with human cells to cause infection. </p>
<p>Many “winter” viruses (including influenza and RSV) are enveloped viruses. Enveloped viruses tend to be <a href="https://www.nature.com/articles/s41598-018-37481-y">more vulnerable to heat and dryness</a> than viruses that lack envelopes. This is one of the reasons why it’s thought that these winter cold viruses survive best in colder winter environments. </p>
<p>While some summer colds (such as enteroviruses) lack an envelope, others (parainfluenza virus 3) have an envelope. In fact, parainfluenza virus 3 is more common when <a href="https://www.nature.com/articles/s41598-018-37481-y">temperatures are high and humidity is low</a> (though it can survive in a range of different humidities). This suggests that other parts of a virus’s structure, aside from the envelope, may play some role in what conditions it can best survive and spread in – but more research will be needed to better understand this.</p>
<p>The interplay between temperature and the immune response to a virus may also play a role. One study found that mice exposed to <a href="https://www.pnas.org/doi/10.1073/pnas.1815029116%23:%7E:text=Here%252C%2520we%2520demonstrated%2520that%2520exposure,responses%2520to%2520influenza%2520virus%2520infection">temperatures of 36°C</a> have a diminished immune response against the flu virus. However, more research is needed to confirm this finding in humans.</p>
<h2>Immune response</h2>
<p>Many people have reported suffering from summer colds this year, leaving many to wonder why this is the case and if the pandemic has played a role.</p>
<p>Immunity to common cold viruses is short-lived. So each season, when we are exposed to new variants, our immune system has to adapt. But during the pandemic, various lockdown measures, such as distancing and wearing masks, limited the exposure that many people had to these viruses. </p>
<p>When we gathered again after lockdown, <a href="https://theconversation.com/qanda-is-the-common-cold-really-much-worse-this-year-170338">cold viruses began to circulate</a>, but our immunity had not been boosted by exposure to that virus the previous year. While the predictability of seasonal viruses has changed since the emergence of COVID, the increases in summer colds seen this year are probably due to us travelling more, more social mixing, less mask wearing and distancing, and less exposure to respiratory viruses the previous year.</p>
<p>This year many parts of the world have also seen extremely hot temperatures and a spate of heatwaves. These temperatures and humidity fluctuations may have played a role in the transmission of common cold viruses this year. These factors will also become even more relevant in the future and may even change what time of year we see certain viruses. Climate change may further <a href="https://camilo-mora.github.io/Diseases/">worsen the spread</a> of <a href="https://www.nature.com/articles/s41558-022-01426-1">viruses in the future</a>.</p>
<p>Since there’s no vaccine for summer colds, the best thing you can do to avoid getting one is to stay away from people who are sick (if possible), wash your hands and avoid touching your face. If you’re unlucky enough to have gotten one, the advice for getting over a cold is the same as it would be if you caught one in the winter: drink plenty of fluids, get lots of rest and eat nutritious foods. To protect others, coughing or sneezing into your elbow or tissues is also recommended.</p>
<p>It may also be worthwhile thinking about how you can protect yourself from getting sick as the temperatures cool in the coming months. The flu vaccine is recommended each winter for certain people, so it’s wise to check if you are due for a flu vaccine this year. This year the flu has been particularly bad for Australia, and predictions suggest it will <a href="https://www1.health.gov.au/internet/main/publishing.nsf/Content/cda-surveil-ozflu-flucurr.htm/$File/flu-09-2022.pdf">be the same</a> for many parts of the world this winter.</p><img src="https://counter.theconversation.com/content/188932/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Fidelma Fitzpatrick does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Some viruses even tend to be more common in the summer than in the winter.Fidelma Fitzpatrick, Consultant Microbiologist, Beaumont Hospital, Dublin, Ireland and Head of Department, Clinical Microbiology, RCSI University of Medicine and Health SciencesLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1812332022-06-02T12:17:20Z2022-06-02T12:17:20ZFuture COVID-19 booster shots will likely need fresh formulations as new coronavirus variants of concern continue to emerge<figure><img src="https://images.theconversation.com/files/466619/original/file-20220601-48323-a2yi45.jpg?ixlib=rb-1.1.0&rect=685%2C319%2C6350%2C4931&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Viral surveillance and prediction may be key parts of figuring out what goes into a vaccine.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/close-up-of-syringe-with-bottles-on-table-pakistan-royalty-free-image/1342313994">Pexels Cover/500px via Getty Images</a></span></figcaption></figure><p>Being up to date on COVID-19 vaccines means having <a href="https://www.cdc.gov/coronavirus/2019-ncov/vaccines/booster-shot.html">had three or four doses</a> of the same shot at this point. Current boosters are the same formulations as the first authorized shots, <a href="https://www.nature.com/articles/d41586-021-02854-3">based on the original strain of the coronavirus</a> that emerged in late 2019. <a href="https://www.cdc.gov/coronavirus/2019-ncov/vaccines/effectiveness/work.html">They do still protect</a> against severe COVID-19, hospitalizations and deaths. But as immunity wanes over time and new, more contagious SARS-CoV-2 variants emerge, the world needs a long-term boosting strategy.</p>
<p><a href="https://scholar.google.com/citations?user=v61MWbsAAAAJ&hl=en&oi=ao">I’m an immunologist</a> who studies immunity to viruses. I was a part of the teams that <a href="https://theconversation.com/how-mrna-vaccines-from-pfizer-and-moderna-work-why-theyre-a-breakthrough-and-why-they-need-to-be-kept-so-cold-150238">helped develop the Moderna</a> and <a href="https://theconversation.com/how-does-the-johnson-and-johnson-vaccine-compare-to-other-coronavirus-vaccines-4-questions-answered-155944">Johnson & Johnson SARS-CoV-2 vaccines</a>, and <a href="https://theconversation.com/what-monoclonal-antibodies-are-and-why-we-need-them-as-well-as-a-vaccine-149356">the monoclonal antibody therapies</a> from Eli Lilly and AstraZeneca.</p>
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<a href="https://images.theconversation.com/files/466621/original/file-20220601-48889-avwg9y.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="out of focus smiling woman extends her arm holding vaccination record card" src="https://images.theconversation.com/files/466621/original/file-20220601-48889-avwg9y.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/466621/original/file-20220601-48889-avwg9y.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=692&fit=crop&dpr=1 600w, https://images.theconversation.com/files/466621/original/file-20220601-48889-avwg9y.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=692&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/466621/original/file-20220601-48889-avwg9y.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=692&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/466621/original/file-20220601-48889-avwg9y.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=870&fit=crop&dpr=1 754w, https://images.theconversation.com/files/466621/original/file-20220601-48889-avwg9y.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=870&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/466621/original/file-20220601-48889-avwg9y.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=870&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">How many lines will ultimately be filled out on your COVID-19 vaccination card?</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/vaccination-cart-royalty-free-image/1347369341">LPETTET/E+ via Getty Images</a></span>
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<p>I often get asked how frequently, or infrequently, I think people are likely to need COVID-19 booster shots in the future. No one has a crystal ball to see which SARS-CoV-2 variant will come next or how good future variants will be at evading vaccine immunity. But looking to other respiratory viral foes that have troubled humanity for a while can suggest what the future could look like. </p>
<p>Influenza virus provides one example. It’s endemic in humans, meaning it hasn’t disappeared and continues to cause recurrent seasonal waves of infection in the population. Every year officials try to predict the best formulation of a flu shot to reduce the risk of severe disease.</p>
<p>As SARS-CoV-2 continues to evolve and is <a href="https://theconversation.com/is-covid-19-here-to-stay-a-team-of-biologists-explains-what-it-means-for-a-virus-to-become-endemic-168462">likely to become endemic</a>, it is possible people may need periodic booster shots for the foreseeable future. I suspect scientists will eventually need to update the COVID-19 vaccine to take on newer variants, as they do for flu.</p>
<h2>Forecasting flu, based on careful surveillance</h2>
<p>Influenza virus surveillance offers a potential model for how SARS-CoV-2 could be tracked over time. Flu viruses have caused several pandemics, including the one in 1918 that killed <a href="https://theconversation.com/10-misconceptions-about-the-1918-flu-the-greatest-pandemic-in-history-133994">an estimated 50 million people worldwide</a>. Every year there are seasonal outbreaks of flu, and every year officials encourage the public to <a href="https://www.cdc.gov/flu/prevent/flushot.htm">get their flu shots</a>.</p>
<p>Each year, health agencies including the World Health Organization’s <a href="https://www.who.int/initiatives/global-influenza-surveillance-and-response-system">Global Influenza Surveillance and Response System</a> make an educated guess based on the flu strains circulating in the Southern Hemisphere about which ones are most likely to circulate in the Northern Hemisphere’s upcoming flu season. Then large-scale vaccine production begins, based on the selected flu strains.</p>
<p>Some flu seasons, the vaccine doesn’t turn out to be a <a href="https://www.cdc.gov/flu/vaccines-work/past-seasons-estimates.html">great match with the virus strains</a> that end up circulating most widely. Those years, the shot is not as good at preventing severe illness. While this prediction process is far from perfect, the flu vaccine field has benefited from strong viral surveillance systems and a concerted international effort by public health agencies to prepare.</p>
<p>While the particulars for influenza and SARS-CoV-2 viruses are different, I think the COVID-19 field should think about adopting similar surveillance systems in the long term. Staying on top of what strains are circulating will help researchers update the SARS-CoV-2 vaccine to match up-to-date coronavirus variants.</p>
<h2>How SARS-CoV-2 has evolved so far</h2>
<p>SARS-CoV-2 faces an evolutionary quandary as it reproduces and spreads from person to person. The virus needs to maintain its ability to get into human cells using its spike protein, while still changing in ways that allow it to evade vaccine immunity. Vaccines are designed to get your body to recognize a particular spike protein, so the more it changes, the higher the chance that the vaccine will be ineffective against the new variant.</p>
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<p>Despite these challenges, SARS-CoV-2 and its variants have successfully evolved to be more transmissible and to better evade people’s immune responses. Over the course of the COVID-19 pandemic, a <a href="https://www.theatlantic.com/science/archive/2022/03/new-covid-variant-mitigation/626980/">new SARS-CoV-2 variant of concern has emerged and dominated</a> transmission in a series of contagion waves every four to seven months. Almost like clockwork, the D614G variant emerged in the spring of 2020 and overtook the original SARS-CoV-2 outbreak strain. In late 2020 and early 2021, the alpha variant emerged and dominated transmission. In mid-2021, the delta variant overtook alpha and then dominated transmission until it was displaced by the omicron variant at the end of 2021.</p>
<p>There’s no reason to think this trend won’t continue. In the coming months, the world may see a dominant <a href="https://www.bloomberg.com/news/articles/2022-04-30/omicron-sublineages-can-evade-antibodies-from-earlier-infections">descendant of the various omicron subvariants</a>. And it’s certainly possible a new variant will emerge from a nondominant pool of SARS-CoV-2, which is how omicron itself came to be.</p>
<p>Current booster shots are simply additional doses of the vaccines based on the outbreak SARS-CoV-2 virus strain that has long been extinct. The coronavirus variants have changed a lot from the original virus, which doesn’t bode well for continued vaccine efficacy. The idea of tailor-made annual shots – like the flu vaccine – sounds appealing. The problem is that scientists haven’t yet been able to predict what the next SARS-CoV-2 variant will be with any degree of confidence.</p>
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<a href="https://images.theconversation.com/files/466624/original/file-20220601-48861-v4usft.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="people walk near a tent marked 'Vaccines | Boosters'" src="https://images.theconversation.com/files/466624/original/file-20220601-48861-v4usft.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/466624/original/file-20220601-48861-v4usft.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/466624/original/file-20220601-48861-v4usft.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/466624/original/file-20220601-48861-v4usft.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/466624/original/file-20220601-48861-v4usft.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/466624/original/file-20220601-48861-v4usft.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/466624/original/file-20220601-48861-v4usft.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">Periodic booster shots may be in order for the foreseeable future.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/covid-vaccine-and-testing-site-is-set-up-outside-of-yankee-news-photo/1390355456">Spencer Platt/Getty Images</a></span>
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<h2>Planning for the future</h2>
<p>Yes, the dominant SARS-CoV-2 variants in the upcoming fall and winter seasons may look different from the omicron subvariants currently circulating. But an updated booster that more closely resembles today’s omicron subvariants, coupled with the immunity people already have from the first vaccines, will likely offer better protection going forward. It might require less frequent boosting – at least as long as omicron sublineages continue to dominate.</p>
<p>The Food and Drug Administration is set to meet in the coming weeks to decide what the fall boosters should be in time for manufacturers to produce the shots. Vaccine makers like Moderna are currently testing their booster candidates in people and <a href="https://thehill.com/policy/healthcare/3473235-moderna-expects-large-amounts-of-omicron-booster-available-by-fall/">evaluating the immune response against newly emerging variants</a>. The test results will likely decide what will be used in anticipation of a fall or winter surge. </p>
<p>Another possibility is to pivot the vaccine booster strategy to include universal coronavirus vaccine approaches that already look promising in animal studies. Researchers are working toward what’s called a universal vaccine which would be effective against multiple strains. Some focus on <a href="https://doi.org/10.1126/science.abi4506">chimeric spikes</a>, which fuse parts of the spike of different coronaviruses together in one vaccine, to broaden protective immunity. <a href="https://clinicaltrials.gov/ct2/show/NCT04784767">Others are experimenting with</a> <a href="https://doi.org/10.1038/s41586-021-03594-0">nanoparticle vaccines</a> that get the immune system to focus on the most vulnerable regions within the coronavirus spike.</p>
<p>These strategies have been shown to ward off difficult-to-stop SARS-CoV-2 variants in lab experiments. They also work in animals against the original SARS virus that caused an outbreak in the early 2000s as well as zoonotic coronaviruses from bats that could jump into humans, causing a future SARS-CoV-3 outbreak.</p>
<p>Science has provided multiple safe and effective vaccines that reduce the risk of severe COVID-19. Reformulating booster strategies, either toward universal-based vaccines or updated boosters, can help steer us out of the COVID-19 pandemic.</p><img src="https://counter.theconversation.com/content/181233/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>David R. Martinez receives funding from the National Institutes of Health, the Howard Hughes Medical Institute, and the Burroughs Wellcome Fund.</span></em></p>A new generation of vaccines and boosters against SARS-CoV-2 may take a page from the anti-influenza playbook, with shots periodically tailored to target the most commonly circulating virus strains.David R. Martinez, Postdoctoral Fellow in Epidemiology, University of North Carolina at Chapel HillLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1798032022-04-21T09:52:27Z2022-04-21T09:52:27ZExercising while sick won’t help you get over a cold faster – but it may prevent your next one<figure><img src="https://images.theconversation.com/files/501918/original/file-20221219-14-rahmat.jpg?ixlib=rb-1.1.0&rect=28%2C42%2C9461%2C6274&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The stress of exercising while sick could potentially make our immune cells less effective.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/african-american-woman-afro-hair-holding-2140316225">Krakenimages.com/ Shutterstock</a></span></figcaption></figure><p>Exercising regularly is <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7149380/">good for your immune system</a> – with some research suggesting that it may even lower the risk of getting <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7172238/">upper respiratory infections</a>, such as the common cold. Even as little as 30 minutes of <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7149380/">moderate exercise five times a week</a> is enough to bring about benefits. </p>
<p>Since exercising is good for our immune system, some people might think that exercising while you’re sick can help you “sweat it out.” Unfortunately, when it comes to the common cold, there’s no evidence exercising while sick can shorten the illness or make it less severe.</p>
<p>There are a couple of reasons why exercise is beneficial for our immune system. The first may be partly explained by the hormones that are released when we exercise. These are called catecholamines – which people may better know as adrenaline and noradrenaline. These hormones play an important role in the functioning of our immune system by eliciting the quick release of important immune cells that help detect the presence of viruses or other pathogens in the body. They also increase the <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7172238/">amount of movement</a> of our immune cells between the blood and tissue – which is important in helping immune cells detect and prevent illnesses caused by viruses or other pathogens. Research shows that exercise is one way we can increase the <a href="https://pubmed.ncbi.nlm.nih.gov/16959907">levels of these important hormones</a> in our body.</p>
<p>When we exercise, it also increases blood flow in order to help our body keep up with the increased demands of exercise. This elevated blood flow places greater <a href="https://pubmed.ncbi.nlm.nih.gov/1618188/">stress</a> on our blood vessels, which releases specific immune cells called <a href="https://www.sciencedirect.com/science/article/pii/S0889159109000610">natural killer cells and T cells</a> that can be found dormant on the walls of our blood vessels. Natural killer cells and T cells both play an important role in killing cells infected with a virus.</p>
<p>Exercise may also benefit our fight against infection in other ways. For example, older adults who regularly exercise over a period of one month <a href="https://academic.oup.com/biomedgerontology/article/60/11/1432/623101?login=true">have been shown to</a> to have quicker skin wound healing compared to a non-exercise control group. This quicker healing process lowers the risk of virus and bacteria entry into the body via skin wounds. </p>
<p>All of these mechanisms together <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7172238/">may improve our immune system</a> and lower the risk of getting sick from viral infections. You don’t even have to be a regular gym-goer to see benefits. <a href="https://journals.lww.com/acsm-msse/Fulltext/2000/07001/Is_infection_risk_linked_to_exercise_workload_.5.aspx">Three studies</a> have shown that when people who didn’t exercise started brisk walking regularly for 40-45 minutes, five days per week, saw 40-50% fewer days of upper respiratory tract infection symptoms when compared to a control group. </p>
<figure class="align-center ">
<img alt="Young adult man and woman go for a brisk walk in the park on a sunny day." src="https://images.theconversation.com/files/459069/original/file-20220421-60275-wf9kgn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/459069/original/file-20220421-60275-wf9kgn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=404&fit=crop&dpr=1 600w, https://images.theconversation.com/files/459069/original/file-20220421-60275-wf9kgn.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=404&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/459069/original/file-20220421-60275-wf9kgn.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=404&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/459069/original/file-20220421-60275-wf9kgn.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=508&fit=crop&dpr=1 754w, https://images.theconversation.com/files/459069/original/file-20220421-60275-wf9kgn.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=508&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/459069/original/file-20220421-60275-wf9kgn.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=508&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">Exercising may reduce your likelihood of catching a cold.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/couple-brisk-walking-dusty-road-230632984">Lester Balajadia/ Shutterstock</a></span>
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<p>Despite the benefits of exercise on our immune system, it’s difficult to know whether exercising while sick with a cold will help you get over your illness quicker than if you don’t exercise. There are currently no studies that have investigated this, largely because of how difficult it would be to conduct this type of study – mostly because some of the participants would purposely need to be infected with a virus to compare whether or not exercising has any affect. Not only would this be difficult to do, it could also be unethical.</p>
<p>So as exercise is good for the immune system, why could exercising while sick not improve the response of the immune system to the infection? Well, it’s important to remember that exercise can stress the body. This stress may in turn make the immune cells <a href="https://journals.humankinetics.com/view/journals/ijsnem/29/2/article-p181.xml?content=pdf">less capable at responding</a> to pathogens. This may be partly due to the fact that the body needs more oxygen and stored energy (in the form of glucose) when we exercise – which our immune cells also need to help fight off a virus. If the body is fighting an existing infection and then exposed to the stress of exercise this may not benefit the immune response. </p>
<p>But while there’s currently no evidence that exercising while sick with a cold can help you get over it faster, that doesn’t mean you can’t exercise if you want to. If your symptoms are <a href="https://www.gssiweb.org/en-ca/article/sse-56-contagious-infections-in-competitive-sports">mainly above the neck</a> (such as a runny nose or congestion), begin by exercising at a lower intensity than you might normally to see how your feeling. If you feel okay, you can gradually increase your intensity. But if exercising makes you feel worse, rest. It’s also not recommended for you to exercise if you’re experiencing fever, aching muscles or vomiting.</p>
<p>If you do want to exercise while you’re sick, make sure you take caution – especially if you exercise around other people. Since colds are infectious, it may be best to skip the gym and exercise outdoors or at home to avoid spreading it around.</p>
<p>Regular exercise is a great way to help prime the immune system to fight many different types of infections, including the common cold and <a href="https://bjsm.bmj.com/content/bjsports/55/19/1099.full.pdf">possibly even COVID-19</a>. But don’t feel you have to exercise if you’re sick. Sometimes the best remedy for a cold is rest, staying hydrated and taking pain-relieving medicines if needed.</p><img src="https://counter.theconversation.com/content/179803/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>John Hough does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>As little as 30 minutes of exercise five times a week can benefit your immune system.John Hough, Senior Lecturer, Exercise Physiology, Nottingham Trent UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1793022022-03-28T03:04:06Z2022-03-28T03:04:06ZWhy do I (and my kids) get so many colds? And with all this COVID around, should we be isolating too?<figure><img src="https://images.theconversation.com/files/454071/original/file-20220324-15-1542vx2.jpg?ixlib=rb-1.1.0&rect=53%2C0%2C6000%2C3997&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://unsplash.com/photos/-CDN2nTKfrA">Brittany Colette</a></span></figcaption></figure><p>As we head towards winter, the likelihood of picking up a pesky cold increases. But COVID changes how we approach sore throats and runny noses. </p>
<p>If you have cold symptoms and return negative rapid antigen tests, isolating isn’t mandatory – but it’s a good idea. But how long should you stay away from others when you have a cold? </p>
<p>Generally, you’re infectious until your symptoms clear, and should stay away until you’re well again. Passing your cold onto others can mean unnecessary COVID testing for them. </p>
<p>Some people may have a lingering cough or other symptoms when they’re past the normal infectious period. If your RAT is clear for COVID and your symptoms linger, it’s a good idea to consult your GP to rule out other infections or complications. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/health-check-i-feel-a-bit-sick-should-i-stay-home-or-go-to-work-42759">Health Check: I feel a bit sick, should I stay home or go to work?</a>
</strong>
</em>
</p>
<hr>
<h2>What causes ‘the common cold’?</h2>
<p>Unlike other infectious diseases with one specific cause – such as COVID, which is caused by SARS-CoV-2 – the “common cold” is a viral upper respiratory tract infection with a set of classic signs and symptoms, but which is not caused by one specific virus. </p>
<figure class="align-center ">
<img alt="Upper respiratory tract graphic." src="https://images.theconversation.com/files/454065/original/file-20220324-17-1oozs5o.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/454065/original/file-20220324-17-1oozs5o.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=462&fit=crop&dpr=1 600w, https://images.theconversation.com/files/454065/original/file-20220324-17-1oozs5o.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=462&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/454065/original/file-20220324-17-1oozs5o.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=462&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/454065/original/file-20220324-17-1oozs5o.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=581&fit=crop&dpr=1 754w, https://images.theconversation.com/files/454065/original/file-20220324-17-1oozs5o.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=581&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/454065/original/file-20220324-17-1oozs5o.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=581&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Common colds affect the upper respiratory tract.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-illustration/respiratory-tract-subdivision-system-involved-process-1798390387">Shutterstock</a></span>
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</figure>
<p>The common cold is most frequently caused by more than 100 different <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3553670/">human rhinovirus</a> serotypes (viruses within one species with the same number and type of surface proteins).</p>
<p>Colds can also be caused by multiple other viruses including <a href="https://journals.lww.com/pidj/Fulltext/2022/03000/Proving_Etiologic_Relationships_to_Disease_.18.aspx">common cold human coronaviruses</a>, <a href="https://onlinelibrary.wiley.com/doi/10.1111/1348-0421.12865">parainfluenza viruses</a>, adenoviruses and others. </p>
<p>We repeatedly get colds because when we develop immunity to one type of virus that can cause colds, another comes along to which we don’t have immunity. Some of these <a href="https://journals.plos.org/plospathogens/article?id=10.1371/journal.ppat.1009453">mutate</a> over time and “escape” from the antibodies we have produced to a previous infection. </p>
<p>While we tend to think of colds as harmless, in the <a href="https://pubmed.ncbi.nlm.nih.gov/17299706/">very young</a>, the elderly or others with less robust immune systems they can cause serious illness. This can result in <a href="https://academic.oup.com/jid/article/185/9/1338/938156">hospitalisation</a> and can trigger <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2972660/#:%7E:text=Viral%20respiratory%20tract%20infections%20were,also%20been%20recorded%20in%20adults.">asthma</a> in susceptible people. </p>
<h2>How are colds transmitted?</h2>
<p>Cold viruses are transmitted through touching your eyes, mouth, nose or food with hands contaminated by viruses, by direct contact with others, or by inhaling contaminated aerosols. </p>
<p><a href="https://www.thelancet.com/journals/lancet/article/PIIS0140673603121629/fulltext">Pre-school children</a> have six to eight (or more) colds per year. </p>
<p><a href="https://www.thelancet.com/journals/lanres/article/PIIS2213-2600(20)30502-6/fulltext">Children</a> appear to be key drivers of community transmission and bring the infection home from pre-school or school. </p>
<figure class="align-center ">
<img alt="Man washes hands with soap." src="https://images.theconversation.com/files/454069/original/file-20220324-19-1tg2ecq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/454069/original/file-20220324-19-1tg2ecq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=387&fit=crop&dpr=1 600w, https://images.theconversation.com/files/454069/original/file-20220324-19-1tg2ecq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=387&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/454069/original/file-20220324-19-1tg2ecq.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=387&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/454069/original/file-20220324-19-1tg2ecq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=486&fit=crop&dpr=1 754w, https://images.theconversation.com/files/454069/original/file-20220324-19-1tg2ecq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=486&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/454069/original/file-20220324-19-1tg2ecq.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=486&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Good hand hygiene reduces the chance of catching a cold.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/coronavirus-pandemic-prevention-wash-hands-soap-1661809675">Shutterstock</a></span>
</figcaption>
</figure>
<p>Adults then take the infections into their workplaces. <a href="https://www.proquest.com/docview/199579881?parentSessionId=xjWwejqtrp8J0ZRdaGuCnrJXCa7Fu2ApCii5oxQKg3U%3D&pq-origsite=360link&accountid=14543">Poor ventilation in workplaces</a> may increase the risk of exposure to cold viruses. </p>
<p>Colds are <a href="https://www.thelancet.com/journals/lancet/article/PIIS0140673603121629/fulltext">more common</a> in autumn, winter and spring, or in the rainy season if you live in the tropics. </p>
<h2>Common cold life cycle</h2>
<p>The median incubation period (the most common time it takes to develop symptoms) <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4327893/">can vary greatly</a> from about half a day to five and half days, depending on which virus is involved. </p>
<p>In a rhinovirus infection it’s roughly <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4327893/">two days</a>, although symptoms can occur in as little as half a day. </p>
<p>Generally, you’re likely to be <a href="https://emedicine.medscape.com/article/227820-overview#a3">infectious one to two days before developing symptoms</a> and while you have symptoms. </p>
<p>Adults and adolescents usually recover from their symptoms in around <a href="https://www.cdc.gov/features/rhinoviruses/index.html">seven to ten days</a>. Coughs may <a href="https://emedicine.medscape.com/article/227820-overview#a6">last longer</a> for some people, particularly <a href="https://www.rch.org.au/kidsinfo/fact_sheets/Cough/#:%7E:text=If%20your%20child%20is%20unwell,from%20school%20for%20that%20long.">younger children</a>. </p>
<h2>What symptoms do you get and why?</h2>
<p><a href="https://emedicine.medscape.com/article/227820-overview#a3">Inflammation</a> from the infection can cause a number of symptoms, <a href="https://www.thelancet.com/journals/lancet/article/PIIS0140673603121629/fulltext">including</a> a sore throat, runny nose, nasal congestion, sneezing and cough. </p>
<p>The runny nose occurs because a chemical called histamine makes your blood vessels more leaky. Your snot starts out clear and runny. Over time it will tend to thicken. </p>
<p>As your immune cells fight off the infection, some white blood cells will die, changing snot colour. As the immune response kicks into high gear, white blood cells called neutrophils produce an infection-fighting chemical (myeloperoxidase) that has a <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3545676/">green colour</a>. </p>
<p>When lots of neutrophils die in the process of fighting the virus, the myeloperoxidase causes green snot. </p>
<p>If your runny nose persists for an extended period, or you develop facial pain, you may have acquired a <a href="https://www.cdc.gov/antibiotic-use/sinus-infection.html">sinus infection</a>. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/curious-kids-why-does-my-snot-turn-green-when-i-have-a-cold-98379">Curious Kids: Why does my snot turn green when I have a cold?</a>
</strong>
</em>
</p>
<hr>
<h2>How to prevent catching and transmitting colds</h2>
<p>The US Centers for Disease Control and Prevention <a href="https://www.cdc.gov/features/rhinoviruses/index.html">recommend the following precautions</a> to reduce the risk to others:</p>
<ul>
<li><p>stay home while symptomatic (and keep sick kids home from school or daycare). For most people, this will be about <a href="https://www.cdc.gov/features/rhinoviruses/index.html">seven to ten days</a> </p></li>
<li><p>if you need to cough or sneeze, do so into your elbow. If using tissues, dispose of contaminated tissues and wash your hands afterwards</p></li>
</ul>
<figure class="align-center ">
<img alt="Child coughs into her arm" src="https://images.theconversation.com/files/454067/original/file-20220324-15-1t3613b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/454067/original/file-20220324-15-1t3613b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/454067/original/file-20220324-15-1t3613b.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/454067/original/file-20220324-15-1t3613b.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/454067/original/file-20220324-15-1t3613b.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/454067/original/file-20220324-15-1t3613b.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/454067/original/file-20220324-15-1t3613b.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Cough into your elbow.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/little-girl-demonstrates-coughing-sneezing-into-38010103">Shutterstock</a></span>
</figcaption>
</figure>
<ul>
<li><p>wash or sanitise your hands frequently because rhinoviruses can linger on fingers <a href="https://bmcinfectdis.biomedcentral.com/articles/10.1186/1471-2334-6-130">and objects</a> for <a href="https://pubmed.ncbi.nlm.nih.gov/25614158/#:%7E:text=Rhinovirus%2DB14%20was%20deposited%20on,had%20no%20influence%20on%20survival.">several hours</a></p></li>
<li><p>transmission occurs when you’re in close proximity to others. So you may choose to work from home, if possible. If you can’t, keep your distance from your co-workers</p></li>
<li><p>given <a href="https://www.thelancet.com/journals/lancet/article/PIIS0140673603121629/fulltext">aerosol transmission is possible</a>, depending on the virus involved, you could also wear a mask at work for a week or two after your symptoms have cleared or if you have returned to work with a lingering cough</p></li>
<li><p>disinfect frequently touched surfaces.</p></li>
</ul>
<p>Finally, train yourself to avoid touching your face. <a href="https://ieeexplore.ieee.org/document/9176589">One study</a> compared upper respiratory tract infections in two groups – one that handwashed only, and one that handwashed and used a Smartwatch with a sensor to track hand movements and give reminders about not touching the face. </p>
<p>The group with the hand-tracking and reminders touched their faces less frequently and had a 53% reduction in upper respiratory tract infections.</p><img src="https://counter.theconversation.com/content/179302/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Thea van de Mortel teaches into the Graduate Infection Prevention and Control programs at Griffith University. </span></em></p>Your rapid antigen tests say you’re COVID-negative but you still have cold symptoms. Generally, you should stay away from others until you’re well again.Thea van de Mortel, Professor, Nursing and Deputy Head (Learning & Teaching), School of Nursing and Midwifery, Griffith UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1724332021-12-17T14:29:10Z2021-12-17T14:29:10ZVitamin D supplements may reduce the duration of the common cold<p>After a couple of years of mask-wearing, social distancing and hand sanitising, the common cold is back. And – according to some people – back with a vengeance. Some are calling it a “<a href="https://www.bbc.co.uk/news/newsbeat-58624295">super cold</a>” – others, “the worst cold ever”. Fortunately, there may be a way to reduce the duration of a cold: vitamin D supplements. </p>
<p>We may suffer more common colds during the winter because we spend more time close to each other indoors. But vitamin D levels might also influence the risk of getting a cold. There are more colds during winter when vitamin D levels are lowest, and fewer colds during summer when vitamin D levels are highest.</p>
<p>We get most of our vitamin D from the sun’s rays (80%–100%) and only a small amount from our diet. For people living at latitudes above 30 degrees, such as in the UK, there is a higher risk of having low vitamin D levels (vitamin D insufficiency) in the winter. People who spend most of their time indoors, or with their skin covered, are also at a higher risk of vitamin D insufficiency. More than half of the UK population is considered to have <a href="https://pubmed.ncbi.nlm.nih.gov/26853300/">insufficient vitamin D levels in winter</a>. </p>
<p>In the UK, the sun’s rays are too weak to provide enough vitamin D between October and March. This means that from October until March, people’s vitamin D levels are likely to fall.</p>
<figure class="align-center ">
<img alt="Man outdoors in shorts and T-shirt." src="https://images.theconversation.com/files/438183/original/file-20211217-19-1cabaoh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/438183/original/file-20211217-19-1cabaoh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=337&fit=crop&dpr=1 600w, https://images.theconversation.com/files/438183/original/file-20211217-19-1cabaoh.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=337&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/438183/original/file-20211217-19-1cabaoh.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=337&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/438183/original/file-20211217-19-1cabaoh.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=424&fit=crop&dpr=1 754w, https://images.theconversation.com/files/438183/original/file-20211217-19-1cabaoh.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=424&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/438183/original/file-20211217-19-1cabaoh.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=424&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Try and spend 15 minutes a day in the sun during spring and summer to top up your vitamin D.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/african-american-man-white-tee-beach-1939023259">Rawpixel/Shutterstock</a></span>
</figcaption>
</figure>
<p>Research shows that vitamin D influences the risk of catching common colds and other respiratory infections. People with lower vitamin D levels are <a href="https://pubmed.ncbi.nlm.nih.gov/19237723/">more likely</a> to have a common cold, and people supplemented with vitamin D are <a href="https://pubmed.ncbi.nlm.nih.gov/28202713/">less likely</a> to get a common cold. </p>
<p>As well as reducing the chance of getting a common cold, our recent <a href="https://pubmed.ncbi.nlm.nih.gov/33481482/">research</a> shows that vitamin D supplementation reduces the severity and duration of common colds.</p>
<p>First, we found that vitamin D-sufficient military recruits were less likely to have a common cold than vitamin D-insufficient recruits during 12 weeks of basic military training. Then we examined the effect of vitamin D supplementation during winter on common colds. We supplemented recruits with either simulated sunlight (UV radiation by a whole-body irradiation cabinet) or oral vitamin D₃ tablets (1,000 IU per day for four weeks to restore vitamin D to normal levels and then 400 IU per day for eight weeks to maintain healthy vitamin D levels). Both supplements similarly achieved vitamin D sufficiency in almost all recruits.</p>
<p>We found that vitamin D supplementation did not reduce the likelihood of getting a common cold, but it did reduce the number of days a participant had a common cold by 36%. It also reduced the peak severity of common cold symptoms by 15%.</p>
<h2>How to get your vitamin D topped up</h2>
<p>Our findings support the <a href="https://www.gov.uk/government/publications/vitamin-d-supplements-how-to-take-them-safely/vitamin-d-supplements-how-to-take-them-safely">UK government’s recommendation</a> to maintain vitamin D sufficiency all year round, and they show a potentially beneficial role of wintertime vitamin D supplementation.</p>
<p>It is not possible to get enough sunlight in the UK between October and March, so it’s advisable to take a 10 microgram vitamin D supplement daily during this period (this value is sometimes shown as 400 IU on the label). If you can’t get any sunlight at all, or you have not supplemented with vitamin D from October onwards, you may need to take 25 micrograms (1,000 IU) of vitamin D for four weeks to restore your vitamin D to a healthy level.</p>
<p>To ensure that you get enough vitamin D during the summer, make sure you get short periods of regular sunlight exposure. Safe sunlight exposure for people living at latitudes between 30 and 60 degrees north involves being in the <a href="https://pubmed.ncbi.nlm.nih.gov/26853300/">sun for 15 minutes</a> between 10am and 3pm while wearing a T-shirt and shorts.</p><img src="https://counter.theconversation.com/content/172433/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Neil Walsh receives funding from MOD UK. </span></em></p><p class="fine-print"><em><span>Sam Oliver receives funding from MOD UK. </span></em></p><p class="fine-print"><em><span>Sophie E Harrison does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Winter vitamin D supplementation may reduce the burden of common coldSophie E Harrison, Research Development and Innovation Officer, Bangor UniversityNeil Walsh, Professor, Director Extremes Research Group, Liverpool John Moores UniversitySam Oliver, Reader in Sport & Exercise Science, Bangor UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1715922021-11-16T19:09:18Z2021-11-16T19:09:18ZWhy did Sydney’s COVID case numbers fall faster than Melbourne’s? Climate may offer clues<p>New daily COVID cases in New South Wales decreased rapidly from a peak of over 1,600 in early September, and are now hovering at about 200–250 new cases per day. </p>
<p>They’ve remained low even since lockdown restrictions were eased on October 11.</p>
<p>By contrast, new daily cases in Victoria have dropped from a peak of over 2,200 on October 13 to plateau around 1,000 – though they have dropped a little further to around 800 in the last few days.</p>
<p>So how come NSW’s cases dropped so much quicker and further than Victoria’s?</p>
<p>The easy answer is that it’s all just luck, good or bad. But if we look hard enough, we can usually find reasons that are likely to provide at least some of the explanation.</p>
<p>Overwhelmed contact tracing and lockdown fatigue affected both states, so it’s unlikely either of these accounted for a major part of the difference between the states’ cases.</p>
<p>It’s more likely structural factors are playing a major role in driving Australia’s diverse epidemic. These include climate and the connectedness of populations.</p>
<p><iframe id="EkDAc" class="tc-infographic-datawrapper" src="https://datawrapper.dwcdn.net/EkDAc/1/" height="400px" width="100%" style="border: none" frameborder="0"></iframe></p>
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<em>
<strong>
Read more:
<a href="https://theconversation.com/why-has-victoria-struggled-more-than-nsw-with-covid-to-a-demographer-theyre-not-that-different-161996">Why has Victoria struggled more than NSW with COVID? To a demographer, they're not that different</a>
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</em>
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<hr>
<h2>Both states’ COVID waves had similarities</h2>
<p>The COVID outbreaks in NSW and Victoria had several similarities. Both quickly took root in the suburbs of each state’s capital city with higher population densities and <a href="https://www.smh.com.au/business/the-economy/how-our-cities-work-essential-lessons-from-lockdown-20211109-p597gn.html">proportions of essential workers</a>.</p>
<p>These regions were also generally younger and so had lower vaccine coverage because our vaccination policy was to gradually progress from older to younger ages.</p>
<p>As the outbreaks spread across both states, populations with lower coverage were often the most severely affected, with outbreaks <a href="https://www.abc.net.au/news/2021-10-06/northern-suburbs-of-melbourne-raise-vaccination-rate/100513594">often affecting suburbs and towns with lagging vaccination rates</a>.</p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1451311391218941972"}"></div></p>
<p>There were also important differences. Sydney’s wave started earlier, when the national rollout was less advanced. But <a href="https://www.smh.com.au/national/nsw/how-blacktown-became-one-of-the-most-vaccinated-lgas-in-nsw-20211026-p5939w.html">targeted vaccination of high-risk suburbs</a> was key to stabilising case numbers.</p>
<p>Strict lockdown measures were implemented earlier in the course of the epidemic in Victoria, and yet were insufficient to achieve a quick return to elimination.</p>
<p>Although contact tracing in NSW has previously been lauded as the country’s “gold-standard”, the effectiveness of any state’s contact tracing rapidly declines as daily case numbers rise through the hundreds. So, differences between the states’ contact tracing is a less likely explanation for the differences in case numbers.</p>
<p>Similarly, <a href="https://www.theguardian.com/australia-news/2021/aug/19/fatigued-not-complacent-as-lockdowns-drag-on-australians-find-it-harder-to-comply-with-covid-restrictions">lockdown fatigue was a factor in both states</a>. Melbourne has spent more days locked down in total, but Sydney’s recent lockdown had started earlier.</p>
<p>Ultimately, both epidemics were controlled through vaccination. Although this has involved both carrot and stick, this can nevertheless be attributed to unprecedented engagement by the public in the vaccination program. Australians have shown how highly motivated they are to get vaccinated once the supply issues were finally resolved, with obvious pay-offs.</p>
<p>So, it’s hard to find a single reason for why the outbreaks played out differently in the two states. While there are several similarities between the two cities’ epidemics, there are also differences, which push in both directions.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/mapping-covid-19-spread-in-melbourne-shows-link-to-job-types-and-ability-to-stay-home-143610">Mapping COVID-19 spread in Melbourne shows link to job types and ability to stay home</a>
</strong>
</em>
</p>
<hr>
<h2>Weather seems to be involved</h2>
<p>In Australia and elsewhere, scientists have frequently proposed <a href="https://www.statnews.com/2020/10/21/covid19-winter-dry-indoor-air-helps-coronavirus-spread/">climatic factors</a> as one explanation for markedly different COVID waves across the world.</p>
<p>This has been difficult to fully define, there are exceptions to any rule, and several analyses <a href="https://www.nature.com/articles/s41467-021-25914-8">have suggested</a> <a href="https://www.nature.com/articles/s41467-021-20991-1">no effect</a>.</p>
<p>Nevertheless, the following factors appear to make COVID outbreaks harder to control:</p>
<ul>
<li><p>higher population density</p></li>
<li><p>higher latitude</p></li>
<li><p>colder and drier weather.</p></li>
</ul>
<p>Since the first explosive epidemics of 2020 in Europe and North America, major high-income cities in winter in temperate regions have often been hit the hardest. For example, New York, Paris and London.</p>
<p>This is consistent with the cyclical pattern of non-COVID coronaviruses, which are responsible for <a href="https://www.science.org/doi/10.1126/science.abe6522">large waves of common cold symptoms</a> each winter.</p>
<p>Several respiratory infections appear to <a href="https://www.medicalnewstoday.com/articles/320099#Cold-air-affects-our-first-line-of-defense">transmit more efficiently in cold, dry climates</a>.</p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1295523173585231872"}"></div></p>
<p>This international pattern appears to have played out similarly in Australia. </p>
<p>Melbourne is a significantly colder and drier city than Sydney, and has needed more restrictions than Sydney to achieve control of COVID. Sydney is colder and drier than Brisbane, and similarly needed more restrictions to gain control.</p>
<p>There are biological reasons why respiratory viruses might transmit more efficiently in cold weather. However, given the importance of indoor transmission to COVID, human behaviour and where we choose to associate at different times of the year may be much of the explanation.</p>
<p>Outside of our major cities on the eastern seaboard, population density and connectedness are likely the dominant factors.</p>
<p>Although we don’t fully understand the contribution of each of these elements, it seems clear structural factors, such as population density, city size, socio-economic status and climate are crucial to how COVID spreads.</p>
<p>We now know vaccination doesn’t just protect against disease and death, but also has a substantial effect on transmission – such that we have the ability to slow COVID outbreaks without necessarily resorting to lockdown.</p>
<h2>How will COVID spread in Australia going forward?</h2>
<p>In our wide, diverse land, we’ll inevitably continue to see different COVID outbreaks in different regions.</p>
<p>Our large cities will likely remain at, or close to, herd immunity through some combination of transmission and vaccination. </p>
<p>Outbreaks will likely occur sporadically in remote areas less connected to major urban centres. Such rural and remote regions may go for months without cases, even with moderate vaccination coverage. However, outbreaks will occur in these communities, particularly as vaccine-induced immunity wanes and long periods without cases lead to complacency about the need for vaccination.</p><img src="https://counter.theconversation.com/content/171592/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>The Epidemiological Modelling Unit at the School of Public Health and Preventive Medicine (led by James Trauer) receives funding from the Victorian Government Department of Health and the World Health Organization.</span></em></p>At this stage it’s hard to know for sure, as there are many differences between the states. But it’s likely that climate plays a role.James Trauer, Associate Professor, Monash UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1700592021-10-20T14:05:05Z2021-10-20T14:05:05ZSix popular beliefs about colds: experts explain the facts<figure><img src="https://images.theconversation.com/files/427491/original/file-20211020-15-1wg9107.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Sticking garlic up your nose will not help you recover from a cold.</span> <span class="attribution"><span class="source">Fizkes/Shutterstock</span></span></figcaption></figure><p><em>As we return to pre-lockdown levels of social mixing, colds are starting to become all too common. A TikTok video has <a href="https://www.tiktok.com/tag/garlicinnose">gone viral</a> involving putting garlic up your nose as a cold cure, just one in a long line of claimed treatments or cures.</em></p>
<p><em>We asked two experts to examine some commonly held beliefs around colds.</em></p>
<p><strong>1. Can you get a cold by getting cold?</strong></p>
<p>Colds become more common in winter. Like other upper respiratory tract infections (in the nose, throat and windpipe) they are normally caused by a virus. There might be a little truth in the idea that getting cold can give you a cold, because as the temperature changes this can alter the lining of our throat and windpipe, <a href="http://www.giargianese.it/wp-content/uploads/2018/04/Exposure-to-cold-and-acute-upper-respiratory-tract-infection.pdf">which can possibly</a> make it easier for viruses to infect cells. However, the main reason we get more colds in winter is spending more time inside, closer to other people – the perfect environment to transmit viruses. </p>
<p><strong>2. Does sticking garlic up your nose help?</strong></p>
<p>The TikTok trend involves putting cloves of garlic up your nose because it claims to act as a decongestant. Sticking something up your nose blocks the flow of mucus, so when it is removed, the flow starts and the mucus drips or even runs out of your nose. Mucus not only helps trap and remove pathogens including viruses, but also contains antibodies and can <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4752725/">reduce how</a> infectious and spreadable viruses are. So this is not a good idea.</p>
<p>Garlic contains a range of compounds which might irritate the nose, and remember sticking anything up your nose isn’t a great idea. It could damage the lining and lead to bleeding or even get stuck. So it doesn’t really help and could be harmful. </p>
<p><strong>3. Can herbal remedies prevent colds?</strong></p>
<p>Various herbal remedies claim to either prevent or speed up recovery from a cold. People often <a href="https://www.nccih.nih.gov/health/echinacea">mention echinacea</a>, a family of plants that grow in North America. Some trials have suggested a small preventative effect, but <a href="https://www.cochrane.org/CD000530/ARI_echinacea-for-preventing-and-treating-the-common-cold">the evidence</a> does not show statistically significant reductions in illness levels. Turmeric is also touted as a preventative medicine, but there is no robust evidence for its effectiveness either.</p>
<figure class="align-center ">
<img alt="A man and a woman with a cold." src="https://images.theconversation.com/files/427490/original/file-20211020-22-8ydkp2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/427490/original/file-20211020-22-8ydkp2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/427490/original/file-20211020-22-8ydkp2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/427490/original/file-20211020-22-8ydkp2.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/427490/original/file-20211020-22-8ydkp2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/427490/original/file-20211020-22-8ydkp2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/427490/original/file-20211020-22-8ydkp2.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Hot drinks can help soothe your sinuses, but they can’t cure a cold.</span>
<span class="attribution"><span class="source">Studio Romantic/Shutterstock</span></span>
</figcaption>
</figure>
<p><strong>4. Can vitamin C help?</strong></p>
<p>Nobel prize-winning scientist <a href="https://pubmed.ncbi.nlm.nih.gov/9350474/#:%7E:text=In%201970%20Linus%20Pauling%20claimed,regards%20the%20size%20of%20benefit.">Linus Pauling</a> suggested that vitamin C in high doses could be an effective treatment for many viral infections. But a <a href="https://www.cochrane.org/">Cochrane review</a>, a very robust system in which researchers assess evidence, found that vitamin C did not <a href="https://pubmed.ncbi.nlm.nih.gov/23440782/">prevent colds</a>, but may reduce their duration, in some people. As vitamin C supplements of around 200mg per day are considered low risk, some suggest this is a reasonable strategy to shorten the effects of a cold.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/pure-fruit-juice-healthy-or-not-122962">Pure fruit juice: healthy, or not?</a>
</strong>
</em>
</p>
<hr>
<p><strong>5. Does vitamin D prevent colds?</strong></p>
<p>Vitamin D has moved from being the sunshine vitamin associated with healthy bones, to being linked to reducing the risks around everything from heart disease and diabetes to viruses. This has included a lot of interest in vitamin D as a way of helping us fight off flu and more recently COVID-19. </p>
<p><a href="https://www.mdpi.com/2072-6643/12/5/1248/htm">Laboratory experiments</a> show that vitamin D is important in supporting immunity and this is critical in fighting off viruses. The problem may be that some people have inadequate vitamin D levels. Sunshine allows us to make our own vitamin D - but that happens less in winter. So it is likely that taking vitamin D supplements as advised by the <a href="https://www.gov.uk/government/publications/vitamin-d-for-vulnerable-groups/vitamin-d-and-clinically-extremely-vulnerable-cev-guidance">UK government</a> over winter is sensible so that you get enough, and this <a href="https://www.bmj.com/content/356/bmj.i6583">may help</a> prevent you from getting a cold.</p>
<p><strong>6. What about chicken soup?</strong></p>
<p>Chicken soup has been used through the ages to treat colds, and <a href="https://ebm.bmj.com/content/26/2/57">like honey</a> it might have some benefits in managing symptoms. But it is unlikely to make a big impact on driving out the infection. The water in the soup will help with hydration, which is a <a href="https://mrmjournal.biomedcentral.com/articles/10.1186/s40248-019-0200-9">often a problem</a> when we have a cold. Like most hot drinks it can help to relieve painful sinuses. There are studies looking at the effect on our <a href="https://www.sciencedirect.com/science/article/abs/pii/S0012369215377217">immune system cells</a>, but the evidence from these is far from conclusive. </p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/kKNqyE3OvZU?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">How to make homemade chicken soup.</span></figcaption>
</figure>
<p>Sadly, there are no miracle cures for the common cold. Some suggestions may be helpful, and are generally not harmful, such as getting enough vitamin C and D. But others are definitely not worth trying and could be risky, such as putting garlic up your nose. The best thing to do is get plenty of rest and drink plenty of fluids to stay hydrated.</p><img src="https://counter.theconversation.com/content/170059/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Duane Mellor has acted in a consultancy role with Kinerva and is a member of the British Dietetic Association.</span></em></p><p class="fine-print"><em><span>James Brown has previously received funding from Seven Seas Ltd (UK).</span></em></p>As winter approaches, every family has a favourite cold remedy, but experts say few work.Duane Mellor, Lead for Evidence-Based Medicine and Nutrition, Aston Medical School, Aston UniversityJames Brown, Associate Professor in Biology and Biomedical Science, Aston UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1648612021-07-21T23:48:17Z2021-07-21T23:48:17ZHow did I catch a cold in lockdown?<figure><img src="https://images.theconversation.com/files/412362/original/file-20210721-15-sjfypw.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C3500%2C2326&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>More than <a href="https://www.abc.net.au/radionational/programs/drive/more-than-13-million-australians-under-lockdown/13462446">half of Australia</a> is in lockdown in an effort to stem the current Delta strain COVID outbreak, with vast numbers of us steering clear of workplaces, school, retail shops, public transport and other busy places. </p>
<p>If, despite all that, you or your children have developed a sniffle, tested negative for COVID and been forced to conclude it’s just a common cold, don’t worry — you’re not alone. </p>
<p>It’s still reasonably easy to catch a cold even during lockdown. The good news is there’s plenty you can do to greatly reduce the risk.</p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"1417425714551214084"}"></div></p>
<h2>We cannot avoid germs altogether</h2>
<p>The air is much more contaminated than many of us would like to believe. So even if we are isolating from humans, we are still breathing in germs all the time. </p>
<p>Most of them don’t make us sick, thanks to our incredible immune system, but sometimes viruses do sneak past our defences. There have even been outbreaks of the common cold on <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2130424/">Antarctic bases</a> after 17 weeks of complete isolation.</p>
<p>Pathogens are part of life, and indeed part of us. We carry around pathogens all the time, including on our skin and up our noses. Most of the time we live <a href="https://www.nih.gov/news-events/news-releases/nih-human-microbiome-project-defines-normal-bacterial-makeup-body">in harmony with them</a>. </p>
<p>However, even though our skin and noses are well designed to stop serious pathogens from entering our body, if there’s a breakdown in a barrier — for example, from picking our nose — that can give them a way to get in. In fact, the commonest ways viruses enter our bodies are through our mouth, nose and eyes, which is why we are always being reminded not to touch our faces.</p>
<h2>You are still out and about</h2>
<p>It’s worth remembering that even during lockdown, many of us still have to go out — for exercise, essential shopping, to seek medical care or for work or compassionate care reasons. So even if you feel locked away and like you’ve not seen friends or family in eons, you have still been out and about.</p>
<p>You can pick up one of the <a href="https://www.cdc.gov/antibiotic-use/colds.html?CDC_AA_refVal=https%3A%2F%2Fwww.cdc.gov%2Fantibiotic-use%2Fcommunity%2Ffor-patients%2Fcommon-illnesses%2Fcolds.html">200 or more viruses</a> that cause what we call the common cold by simply touching a shop counter when you pick up essential groceries, then rubbing the germ into your eye. </p>
<p>Perhaps you pushed a child on the swings and then touched your nose or mouth. A child might have picked up a cold at the playground and brought it home. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/412363/original/file-20210721-23-1mbuisj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/412363/original/file-20210721-23-1mbuisj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/412363/original/file-20210721-23-1mbuisj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/412363/original/file-20210721-23-1mbuisj.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/412363/original/file-20210721-23-1mbuisj.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/412363/original/file-20210721-23-1mbuisj.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/412363/original/file-20210721-23-1mbuisj.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/412363/original/file-20210721-23-1mbuisj.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Rubbing your eye is a one way to transfer a germ from your hand to your body.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<p>Viruses that cause the common cold include rhinovirus (which can be <a href="https://www.atsjournals.org/doi/full/10.1164/rccm.200306-760OC">airborne</a> and can survive for <a href="https://journals.asm.org/doi/abs/10.1128/aem.59.5.1579-1585.1993">hours</a> on surfaces under certain conditions). Another virus that causes colds is adenovirus, which can be <a href="https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0033974">airborne</a> and has been detected on <a href="https://onlinelibrary.wiley.com/doi/abs/10.1002/jmv.23907">surfaces</a>.</p>
<p>Once you have actually picked up a cold virus, it may take days before you actually get sick — this is what we call the incubation period, meaning the time between infection with the pathogen, and the onset of symptoms. </p>
<p>Cold viruses can incubate for many <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4327893/">days</a>, so it’s possible that even though you or your household members are getting a sniffle now, it was a germ picked up some time ago that has just been biding its time. </p>
<p>And remember: not all “coughs and colds” are actually caused by a virus. For example, whooping cough seems very much like “just a cold” when you first get sick with it. Whooping cough is actually caused by a bacterium, and can survive <a href="https://www.cdc.gov/vaccines/pubs/pinkbook/downloads/pert.pdf">up to 42 days</a> before it declares itself. For example, my son managed to “catch” whooping cough more than two weeks into lockdown last year. It’s highly likely he picked it up from another child at school before lockdown began, but only developed the cough a fortnight later. Incidentally, he was fully vaccinated as a baby.</p>
<h2>Washing hands and wearing masks</h2>
<p>What all this shows is that many of us are not as great at washing our hands as we would like to think. Even surgeons, who know how to scrub exceptionally well, still sometimes pass on infections to patients. Viruses are just excellent at surviving and getting past our defences. </p>
<p>So if you’d like to reduce your chances of getting a cold during lockdown — and goodness knows it’s the last thing you need when you’ve got so much else on your plate — remember <a href="https://www.cdc.gov/features/rhinoviruses/index.html">the basics</a>. </p>
<p>Wash hands often, don’t share utensils, avoid touching your nose, mouth and eyes, wear a mask when you leave the house, and try not to get too close to any other household members who may be coughing and sneezing.</p><img src="https://counter.theconversation.com/content/164861/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Natasha Yates is a member of RACGP.</span></em></p>It’s still reasonably easy to catch a cold even during lockdown.Natasha Yates, Assistant Professor, General Practice, Bond UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1612642021-05-31T06:04:08Z2021-05-31T06:04:08ZWhat causes dry lips, and how can you treat them? Does lip balm actually help?<figure><img src="https://images.theconversation.com/files/403491/original/file-20210531-27-1pcrc50.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C6000%2C3997&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><span class="source">Shutterstock</span></span></figcaption></figure><p>As we head into the colder weather, many of us might be afflicted with the irritating ailment of dry and chapped lips.</p>
<p>People have been trying to figure out how to fix dry lips for centuries. Using beeswax, olive oil and other natural ingredients have been reported as early as Cleopatra’s <a href="https://nationalpost.com/entertainment/movies/secret-gloss-a-brief-history-of-lip-balm-from-earwax-to-clorox">time</a>, around 40 B.C.</p>
<p>In 1833, there were even reports of human earwax being <a href="https://www.google.com.au/books/edition/The_American_Frugal_Housewife/-YYSAQAAMAAJ?hl=en&gbpv=1&dq=the+American+Frugal+Housewife,+Dedicated+to+Those+who+are+Not+Ashamed+of+Economy&printsec=frontcover">recommended</a> as a successful remedy for dry, cracked lips. Not long after, the first commercial lip balms hit the market.</p>
<p>So what causes dry lips, and which lip balms actually help? The key is to avoid lip balms that contain certain additives which might worsen the problem.</p>
<p><div data-react-class="InstagramEmbed" data-react-props="{"url":"https://www.instagram.com/p/CPhuZbctAHL","accessToken":"127105130696839|b4b75090c9688d81dfd245afe6052f20"}"></div></p>
<h2>They need to be soft but resilient</h2>
<p>Our lips are constantly exposed to the elements, such as sunlight, wind, dry air, and cold weather. They have to withstand our daily lifestyle, including contact with food, cosmetics, biting, picking, rubbing against clothes, kissing and more.</p>
<p>So, although they look soft and fleshy, our lips need to be resilient and tough.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/curious-kids-why-do-our-toes-and-fingers-get-wrinkly-in-the-bath-120229">Curious Kids: why do our toes and fingers get wrinkly in the bath?</a>
</strong>
</em>
</p>
<hr>
<p>Lips sit at the junction where our outside facial skin transitions into the <a href="https://www.youtube.com/watch?v=XsrlJn2cDh0&t=58s">tissue</a> layers lining the mouth. As such, the lips are structured similar to <a href="https://www.ncbi.nlm.nih.gov/books/NBK507900/">mucous membranes</a>, but with the addition of a <a href="https://link.springer.com/article/10.1007/s004030050453">protective</a> outside layer of skin. Lips don’t have hair follicles, or sweat, saliva and oil glands.</p>
<p>This unique structure means they’re particularly prone to dryness as they have a much lower ability to hold <a href="https://europepmc.org/article/med/15030342">water</a> than the rest of the face’s skin.</p>
<h2>What causes dry lips?</h2>
<p>Many of us get dry lips at certain times of the year. This can occur naturally, or be brought on by many different factors, including:</p>
<ul>
<li><p>inflamed lips, known as <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6531998/">cheilitis</a>. This can be due to a skin condition, or an infection such as herpes or cold sores</p></li>
<li><p><a href="https://journals.lww.com/dermatitis/Abstract/2007/12000/Allergic_Contact_Cheilitis_from_Benzophenone_3_in.8.aspx">allergies</a></p></li>
<li><p>medications which impact the <a href="https://pubmed.ncbi.nlm.nih.gov/12974516/">salivary glands</a>, the mouth’s surrounding <a href="https://youtu.be/UNyKlwO23w4">muscles</a>, or sensations throughout the lip area</p></li>
<li><p>tongue injuries, teeth that rub against the lips, or other dental issues</p></li>
<li><p>poor oral health. This can be brought on by general neglect, <a href="https://pubmed.ncbi.nlm.nih.gov/22750232/">eating disorders</a>, or bad oral hygiene habits</p></li>
<li><p>burns, such as eating food that’s too hot, or sunburn. Burns can result in the lips swelling, <a href="https://youtu.be/T-FnAH9y1N4">scarring</a> and blistering, and it may take a long time for the pain to alleviate</p></li>
<li><p>some diseases or disorders, such as <a href="https://pubmed.ncbi.nlm.nih.gov/19445445/">Sjögren’s syndrome</a></p></li>
<li><p>dehydration, heat stroke, <a href="https://youtu.be/BxgEoLmOACo">fever</a>, or excessive heat</p></li>
<li><p><a href="https://www.sciencedirect.com/science/article/pii/S2352647520300988?via%3Dihub">nasal</a> congestion, which leads to chronic mouth-breathing. This can sometimes be a result of illness, such as when you have a common cold</p></li>
<li><p>cold weather or cold wind that runs along the lips and removes moisture</p></li>
<li><p>persistent licking, which can create a wet-dry cycle that excessively <a href="https://www.sciencedirect.com/science/article/pii/S2352647520300988">dries</a> out your lips.</p></li>
</ul>
<p>The dryness can also lead to pain, itching or stinging.</p>
<p>If dry lips start causing serious issues, it may be helpful to discuss this with a medical professional.</p>
<h2>How can you treat dry lips?</h2>
<p>It is important to identify what’s causing dry lips. If it’s due to lip licking, then you need to make habitual changes to stop the practice. If it’s due to cold, windy or dry weather, then certain balms and ointments can help protect the lips. </p>
<p>Drinking adequate amounts of <a href="https://www.sciencedirect.com/science/article/pii/S2352647520300988">water</a> can assist, because this helps prevent dry skin in general.</p>
<p>If this isn’t enough, bland, non-irritating, unflavoured lip balms can help, as they act as a film covering the lip surface, keeping moisture in.</p>
<figure class="align-center ">
<img alt="Man with beard applying lip balm" src="https://images.theconversation.com/files/403497/original/file-20210531-15-u2nxjk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/403497/original/file-20210531-15-u2nxjk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/403497/original/file-20210531-15-u2nxjk.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/403497/original/file-20210531-15-u2nxjk.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/403497/original/file-20210531-15-u2nxjk.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=502&fit=crop&dpr=1 754w, https://images.theconversation.com/files/403497/original/file-20210531-15-u2nxjk.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=502&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/403497/original/file-20210531-15-u2nxjk.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=502&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">It’s best to choose a bland lip balm that doesn’t contain fragrances, flavours and colours.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
</figcaption>
</figure>
<p>In many cases these use petroleum jelly as a base (although it’s not <a href="https://onlinelibrary.wiley.com/doi/10.1111/ics.12533">required</a>), along with refined mineral oils to remove any <a href="https://www.hindawi.com/journals/jchem/2019/1680269/">hazardous</a> compounds, and other ingredients that can assist in retaining and maintaining a <a href="https://onlinelibrary.wiley.com/doi/full/10.1111/ics.12583">barrier function</a>. </p>
<p>In the race to appeal to consumers, cosmetic manufacturers have trialled a number of new ingredients in their lip balms. Popular lip balms often contain additives which can make the balm smell or taste nice, or soften the feel when it rubs against the lips.</p>
<p>Some of these extra ingredients can help. For example, if you’re out in the sun a lot, lip balm with included sunscreen is a <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1227745/">great</a> addition.</p>
<h2>Products to avoid</h2>
<p>In many cases, these compounds provide the feeling of immediate relief on the lips but don’t actually help with the barrier function. And in some cases, they can become irritants and even worsen the dryness.</p>
<p>When choosing a lip balm, try to avoid products containing these ingredients:</p>
<ul>
<li><p><a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6477564/">fragrances</a></p></li>
<li><p><a href="https://enveurope.springeropen.com/articles/10.1186/s12302-016-0076-7">flavours</a>, such as mint, citrus, vanilla, and cinnamon</p></li>
<li><p>shiny <a href="https://www.nbcnews.com/health/health-news/not-just-lip-service-gloss-can-invite-skin-cancer-flna1c9459959">glosses</a>, which can intensify damage from the sun’s rays</p></li>
<li><p><a href="https://www.fda.gov/cosmetics/cosmetic-ingredient-names/color-additives-permitted-use-cosmetics">colours</a>, which can cause irritation and do nothing to assist the barrier function</p></li>
<li><p>menthol, phenol or salicylic acid, which can actually make your lips <a href="https://health.clevelandclinic.org/7-signs-your-lip-balm-use-is-just-a-bad-habit/">drier</a></p></li>
<li><p>additional, unnecessary <a href="https://www.aad.org/public/everyday-care/skin-care-basics/dry/heal-dry-chapped-lips">ingredients</a> such as camphor, lanolin, octinoxate, oxybenzone or propyl gallate.</p></li>
</ul>
<p>And be sure to stop biting, picking or excessively licking your lips.</p>
<p>Staying hydrated and applying a bland lip balm should be a routine incorporated into your every day lifestyle for healthy, protected, and moisturised lips.</p>
<p><div data-react-class="InstagramEmbed" data-react-props="{"url":"https://www.instagram.com/p/CPhDQOdjh5a","accessToken":"127105130696839|b4b75090c9688d81dfd245afe6052f20"}"></div></p><img src="https://counter.theconversation.com/content/161264/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>The authors do not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>The key is to avoid lip balms that contain certain additives which might worsen the problem. Instead, try balms that are bland and don’t contain flavours, fragrances and colours.Christian Moro, Associate Professor of Science & Medicine, Bond UniversityCharlotte Phelps, PhD Student, Bond UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1584612021-04-07T09:36:11Z2021-04-07T09:36:11ZThe common cold might protect you from coronavirus – here’s how<figure><img src="https://images.theconversation.com/files/393556/original/file-20210406-17-tqm7q8.jpg?ixlib=rb-1.1.0&rect=131%2C122%2C5299%2C3432&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The common cold is usually caused by a rhinovirus.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/ill-african-young-woman-covered-blanket-1444224857">Shutterstock/fizkes</a></span></figcaption></figure><p>We often assume that viral infections are caused by individual virus types. But in reality, we’re exposed to many viruses on a day to day basis, and co-infection – where someone is simultaneously infected by two or more virus types – is quite common. </p>
<p>The cells lining our throat and lower airways are exposed to the environment around us, making them a prime target for co-infection by respiratory viruses. These range from common-cold-causing rhinoviruses to the more serious influenza viruses, which are often the cause of global pandemics.</p>
<p>One of the most frequent outcomes of co-infection is viral interference, a phenomenon where one virus out-competes and suppresses the replication of <a href="https://cmr.asm.org/content/31/4/e00111-17">the other co-infecting viruses</a>. Interestingly, a growing body of evidence suggests rhinoviruses may interfere with the replication of other respiratory viruses that tend to be more serious. They may even offer the host temporary protection from them.</p>
<p>The good news is that this appears to include SARS-CoV-2 – the virus responsible for COVID-19. In <a href="https://academic.oup.com/jid/advance-article/doi/10.1093/infdis/jiab147/6179975">a new study</a>, rhinoviruses have been shown to suppress the replication of this virus. </p>
<h2>Rhinoviruses</h2>
<p>The majority of respiratory viruses that infect humans are rhinoviruses (from the Greek “rhino” for “of the nose”). First identified in 1953, rhinoviruses are extremely small respiratory viruses that are present all over the world. As far as we know, they are only capable of infecting humans. </p>
<p>Rhinovirus infections can be serious in some cases. However, they usually infect us to cause the common cold, a relatively mild disease. In response to such an infection, our immune system produces virus-killing molecules called interferons.</p>
<p>Interferons are produced in response to infections by all types of viruses, but they’re produced much <a href="https://doi.org/10.1093/infdis/jiab147">faster and in greater quantities</a> in response to rhinovirus compared to other respiratory viruses. Despite this, rhinoviruses have evolved complex mechanisms that allow them to evade interferons and replicate efficiently. It’s widely accepted that the rhinovirus-induced interferon response is what produces the <a href="https://doi.org/10.1016/j.coviro.2012.03.008">symptoms of the common cold</a>, rather than the virus itself.</p>
<figure class="align-center ">
<img alt="A computer generated illustration of rhinoviruses." src="https://images.theconversation.com/files/393561/original/file-20210406-23-1jiqhx4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/393561/original/file-20210406-23-1jiqhx4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/393561/original/file-20210406-23-1jiqhx4.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/393561/original/file-20210406-23-1jiqhx4.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/393561/original/file-20210406-23-1jiqhx4.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/393561/original/file-20210406-23-1jiqhx4.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/393561/original/file-20210406-23-1jiqhx4.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Rhinos without horns.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-illustration/molecular-model-rhinovirus-virus-that-causes-1054047338">Shutterstock/Kateryna Kon</a></span>
</figcaption>
</figure>
<p>While rhinoviruses are pretty resistant to interferons, some other respiratory viruses are extremely sensitive to them. Influenza viruses, for example, can’t replicate properly in the presence of interferons.</p>
<p>Since rhinovirus infections trigger such a huge interferon response, researchers had the idea that they might offer protection against infection by more deadly, interferon-sensitive viruses, such as influenza. </p>
<p>In recent years, several research groups have investigated this phenomenon in the lab. They found that when cells are infected with rhinovirus, it triggers an interferon response which prevents them from being <a href="https://doi.org/10.1073/pnas.1911083116">infected with</a> the influenza virus. </p>
<p>If rhinovirus infections block the replication of other respiratory viruses, this could affect their spread and patterns of distribution. For instance, <a href="https://doi.org/10.1016/S2666-5247(20)30114-2">evidence suggests</a> that rhinovirus may have interrupted the spread of the H1N1, or “swine flu”, influenza virus during the 2009 global pandemic.</p>
<h2>The cold and COVID-19</h2>
<p>If rhinovirus infections can interfere with the replication and spread of pandemic influenza viruses, could it do the same for interferon-sensitive coronaviruses, such as SARS-CoV-2? </p>
<p>A team of scientists at the University of Glasgow recently set out to answer this question. They infected lab-grown layers of cells that replicates the conditions in the human respiratory tract with rhinovirus, SARS-CoV-2 and both viruses simultaneously. </p>
<p>Interestingly, SARS-CoV-2 replicated much slower in the co-infection scenario. But rhinovirus replication didn’t change in the presence or absence of SARS-CoV-2. </p>
<p>To better replicate real-life conditions, the authors also infected the cells with either rhinovirus or SARS-CoV-2 24 hours prior to co-infecting them with the other virus. Rhinovirus was able to suppress the replication of SARS-CoV-2 regardless of whether it was added before or after SARS-CoV-2, suggesting that rhinovirus infection actively protects the cells from SARS-CoV-2. </p>
<p>Next, the authors wanted to confirm that the inhibitory effect on SARS-CoV-2 replication was specifically caused by a rhinovirus-induced interferon response. They co-infected cells with both rhinovirus and SARS-CoV-2 in the presence of a drug which blocks the virus-killing properties of interferons, called BX795. </p>
<p>In this part of the experiment, BX795 allowed SARS-CoV-2 to replicate at a level comparable to that of a single SARS-CoV-2 infection. This confirmed that a rhinovirus-induced interferon response is indeed responsible for the block in SARS-CoV-2 replication seen in the co-infection experiments without BX795. </p>
<p>Using mathematical simulations, the authors also found that more frequent rhinovirus infections among the population would result in a reduced rate of SARS-CoV-2 infection. Taken together, these results confirm that rhinovirus infections suppress the replication of SARS-CoV-2, which may in turn reduce the number of new cases among the population.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/the-end-of-the-pandemic-is-coming-just-dont-set-a-date-for-the-party-157205">The end of the pandemic is coming – just don't set a date for the party</a>
</strong>
</em>
</p>
<hr>
<p>So, can rhinoviruses protect us from infection by SARS-CoV-2? The short answer is yes. However, it’s essential to note that the rhinovirus-induced interferon response is an example of innate immunity, meaning that its effect only lasts as long as the invading rhinovirus is in your body.</p>
<p>If you recover from a cold and then come into contact with SARS-CoV-2 a week later, it’s unlikely you will have enough interferons to successfully block the SARS-CoV-2 infection. Long-term immunity, which involves the production of highly specific antibodies, is only obtained by coming into direct contact with the virus in question – either in the wild or by vaccination. </p>
<p>So, if you’re someone who has not yet had COVID-19 or are unvaccinated, you’ll only be protected if you are lucky enough to be infected at the same time that you’re experiencing a cold. Rhinoviruses may play a critical role in controlling the spread of SARS-CoV-2 among the human population. The most effective way, however, probably remains vaccination.</p><img src="https://counter.theconversation.com/content/158461/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Matthew James receives funding from the Department for the Economy, Asthma UK and the Medical Research Foundation. </span></em></p>Rhinoviruses may play a critical role in controlling the spread of SARS-CoV-2 among the human population.Matthew James, Research Assistant, Wellcome-Wolfson Institute for Experimental Medicine, Queen's University BelfastLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1519102020-12-15T20:16:45Z2020-12-15T20:16:45ZWill going out in the cold give you a cold?<figure><img src="https://images.theconversation.com/files/374912/original/file-20201214-13-t6d99c.jpg?ixlib=rb-1.1.0&rect=33%2C0%2C5573%2C3732&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Viruses spread easier during the winter than other times of the year, but being outside isn't the main cause of transmission.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/man-shovels-the-sidewalk-outside-of-his-suburban-royalty-free-image/564190027?adppopup=true">Christopher Kimmel via Getty Images</a></span></figcaption></figure><p>Many of us have heard: “Don’t go outside without a coat; you’ll catch a cold.” </p>
<p>That’s not exactly true. As with many things, the reality is more complicated. Here’s the distinction: Being cold isn’t why you get a cold. But it is true that cold weather makes it easier to get the cold or flu. It is still too early to tell how weather impacts the COVID-19 virus, but scientists are starting to think it behaves differently than cold and flu viruses.</p>
<p>As an <a href="https://www.purdue.edu/aging/faculty/?id=256">associate professor of nursing</a> with a background in public health, I’m asked about this all the time. So here’s a look at what actually happens. </p>
<p>Many viruses, including <a href="https://doi.org/10.1073/pnas.1411030112">rhinovirus</a> – the usual culprit in the common cold – and influenza, remain infectious longer and replicate faster in colder temperatures. That’s why these viruses spread more easily in winter. Wearing a heavy coat won’t necessarily make a difference. </p>
<figure class="align-center ">
<img alt="Two women outside during the winter." src="https://images.theconversation.com/files/374894/original/file-20201214-24-1f7enxs.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/374894/original/file-20201214-24-1f7enxs.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/374894/original/file-20201214-24-1f7enxs.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/374894/original/file-20201214-24-1f7enxs.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/374894/original/file-20201214-24-1f7enxs.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/374894/original/file-20201214-24-1f7enxs.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/374894/original/file-20201214-24-1f7enxs.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The cold weather does have an impact on whether or not you catch a cold.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/two-women-take-a-selfie-photo-in-front-of-a-frozen-fountain-news-photo/899344332?adppopup=true">Spencer Platt via Getty Images</a></span>
</figcaption>
</figure>
<h2>Virus transmission is easier when it’s cold</h2>
<p>More specifically, cold weather can <a href="https://www.nih.gov/news-events/nih-research-matters/flu-virus-fortified-colder-weather">change the outer membrane</a> of the influenza virus; it makes the membrane more solid and rubbery. Scientists believe that the rubbery coating makes person-to-person transmission of the virus easier. </p>
<p>It’s not just cold winter air that causes a problem. Air that is dry in addition to cold has been linked to flu outbreaks. A National Institutes of Health study suggests that <a href="https://www.nih.gov/news-events/nih-research-matters/dry-air-may-spur-flu-outbreaks">dry winter air</a> further helps the influenza virus to remain infectious longer. </p>
<p>How your immune system responds during cold weather also matters a great deal. <a href="https://doi.org/10.1038/nature.2013.13025">Inhaling cold air</a> may adversely affect the immune response in your respiratory tract, which makes it easier for viruses to take hold. That’s why wearing a scarf over your nose and mouth may help. </p>
<p>Also, most people get less sunlight in the winter. That is a problem because the <a href="https://theconversation.com/why-you-need-more-vitamin-d-in-the-winter-128898">Sun is a major source of vitamin D</a>, which is essential <a href="https://doi.org/10.1016/j.mayocp.2013.05.011">for immune system health</a>. Physical activity, another factor, also tends to drop <a href="https://doi.org/10.1007/s10238-020-00650-3">during the winter</a>. People are <a href="https://doi.org/10.1016/j.jshs.2016.07.007">three times more likely</a> to delay exercise in snowy or icy conditions.</p>
<p>Instead, people spend more time indoors. That usually means more close contact with others, which leads to disease spread. Respiratory viruses generally spread within a six-foot radius of an infected person. When you are indoors, it is very likely that you are closer together than six feet. </p>
<p>In addition, cold weather <a href="https://www.texashealthflowermound.com/how-cold-weather-affects-your-ear-nose-throat/">dries out</a> your eyes and the mucous membranes in your nose and throat. Because viruses that cause colds and flu are typically inhaled, the virus can attach more easily to these impaired, dried-out passages.</p>
<figure class="align-center ">
<img alt="A child in bed with a cold." src="https://images.theconversation.com/files/374909/original/file-20201214-19-eqxul0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/374909/original/file-20201214-19-eqxul0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/374909/original/file-20201214-19-eqxul0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/374909/original/file-20201214-19-eqxul0.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/374909/original/file-20201214-19-eqxul0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/374909/original/file-20201214-19-eqxul0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/374909/original/file-20201214-19-eqxul0.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Spending more time indoors can increase the chances of catching a cold.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/girl-sleeping-with-sickness-on-the-bed-royalty-free-image/926062370?adppopup=true">Rawpixel via Getty Images</a></span>
</figcaption>
</figure>
<h2>What you can do</h2>
<p>While the bottom line is that being wet and cold doesn’t make you sick, there are strategies to help prevent illness all year long. </p>
<ul>
<li><p>Wash your hands often. </p></li>
<li><p>Avoid touching your face, something people do <a href="https://theconversation.com/how-to-stop-touching-your-face-to-minimize-spread-of-coronavirus-and-other-germs-133683">between nine and 23 times an hour</a>. </p></li>
<li><p>Stay hydrated; <a href="https://www.mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/in-depth/water/art-20044256">eight glasses a day</a> of water is a good goal, but that could be more or less depending on lifestyle and the size of the person. </p></li>
<li><p>Eat a well-balanced diet. Dark green, leafy vegetables are rich in immune system-supporting vitamins; eggs, fortified milk, salmon and tuna have vitamin D. </p></li>
<li><p>Stay physically active, even during the winter. </p></li>
<li><p>Clean the hard, high-touch surfaces in your home often. </p></li>
<li><p>If your nose or throat gets dry in the winter, consider using a humidifier.</p></li>
<li><p>Get the flu vaccine. </p></li>
</ul>
<p>And one more important thing this year: When it’s your turn, make sure you get the COVID-19 vaccine.</p>
<p>[<em><a href="https://theconversation.com/us/newsletters/science-editors-picks-71/?utm_source=TCUS&utm_medium=inline-link&utm_campaign=newsletter-text&utm_content=science-corona-important">The Conversation’s most important coronavirus headlines, weekly in a new science newsletter</a>.</em>]</p><img src="https://counter.theconversation.com/content/151910/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Libby Richards does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Going out in the cold won’t necessarily lead to you getting a cold. But cold weather in general is more hospitable to viruses, so it’s wise to take steps to keep your immune system strong.Libby Richards, Associate Professor of Nursing, Purdue UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1475472020-11-17T15:50:55Z2020-11-17T15:50:55ZAntibiotics in cold and flu season: Potentially harmful and seldom helpful<figure><img src="https://images.theconversation.com/files/368064/original/file-20201107-17-ynhp4y.jpg?ixlib=rb-1.1.0&rect=677%2C201%2C5432%2C3884&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Antibiotics do not shorten or reduce the severity of colds or flu, but they could produce adverse effects that make you feel even worse.</span> <span class="attribution"><span class="source">(Pexels/Andrea Piacquadio)</span></span></figcaption></figure><p>Antibiotics are <a href="https://doi.org/10.1503/cmaj.109-5742">over-prescribed in Canada</a> and <a href="https://doi.org/10.1001/jama.2016.4151">worldwide</a>, often for infections that do not need their help, <a href="https://www.cdc.gov/mmwr/preview/mmwrhtml/mm6034a1.htm">particularly respiratory conditions</a>. While these unnecessary prescriptions may contribute to the development of <a href="https://theconversation.com/antibiotic-resistant-infections-could-destroy-our-way-of-life-new-report-126670">resistant bacteria</a>, there is another reason to be cautious about antibiotics: Direct harms caused by these drugs.</p>
<p>Our group — a family physician, an infectious disease specialist and a health sciences student — has published <a href="https://www.cfp.ca/content/66/9/651">a review of the evidence about adverse effects of antibiotics commonly used in the community</a>. Even though two of us are experienced physicians, and knew about many problems with drugs, we were surprised by the frequency and severity of some of these effects.</p>
<h2>Gut reactions, allergies and skin rashes</h2>
<p>The review showed that for many antibiotics, over 10 per cent of patients get gut reactions, such as stomach pain, discomfort or diarrhea. This is particularly common in children given antibiotics for ear and throat infections.</p>
<p>Every antibiotic causes allergic reactions in some people. A few allergic reactions cause swelling of the mouth and airways, needing immediate treatment with adrenalin and other drugs. </p>
<p>Other allergic reactions are just a skin rash, but this is often very irritating, and in some it may progress to cause severe blistering. Such severe reactions can be caused by sulfonamide drugs, often used to treat urinary tract infections. In Canada, a medication combining the antibiotic trimethoprim and a sulfa drug is often used for this purpose. However, using trimethoprim alone — a common practice in Europe — reduces the risk of allergic reactions.</p>
<figure class="align-center ">
<img alt="Red and white pill capsules scattered on a white surface beside a glass of water." src="https://images.theconversation.com/files/368066/original/file-20201107-17-a4sy62.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/368066/original/file-20201107-17-a4sy62.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/368066/original/file-20201107-17-a4sy62.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/368066/original/file-20201107-17-a4sy62.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/368066/original/file-20201107-17-a4sy62.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/368066/original/file-20201107-17-a4sy62.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/368066/original/file-20201107-17-a4sy62.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">In mononucleosis patients, amoxycillin can cause a severe skin rash that looks just like an allergy.</span>
<span class="attribution"><span class="source">(Piqsels)</span></span>
</figcaption>
</figure>
<p>A severe skin rash occurs in as many as one-third of people given amoxycillin for infectious mononucleosis (glandular fever), a common cause of sore throat in adolescents and young adults. This looks just like an allergy, so these people may be told they are allergic, which prevents use of penicillins even when they would be the best drug to use. A skin test can show that it is not an allergy, in which case penicillins may be used in future.</p>
<p>In rare cases, antibiotics cause other serious reactions, including some that are fatal. They can cause serious damage to lungs, liver, kidneys, nerves and joints. For example quinolones, a common group of antibiotics (the most well known is ciprofloxacin), can cause ruptured tendons and damage to nerves that causes tingling and numbness. Minocycline, often used to treat acne, can cause <a href="https://doi.org/10.1503/cmaj.200012">dark pigmentation of the face, as well as neurological effects</a>.</p>
<h2>Benefits vs. risks</h2>
<p>With antibiotics, the likelihood of benefit must be balanced against the chance of harm they may cause. When someone has a serious infection, it is worth taking the risk of harms, to gain the benefits of cure. But for a mild infection that the immune system will defeat by itself, there is no benefit from the antibiotic, only a chance of harm. So a prescription for antibiotics can be worse than useless.</p>
<p>Antibiotics are among our most commonly used drugs. However, they should not be thought of as necessary to cure any infection. For most infections, they only help to tip the balance in favour of our immune system.</p>
<p>Antibiotics work on bacterial infections such as pneumonia or cellulitis, and these illnesses improve faster with the right antibiotic.</p>
<figure class="align-right ">
<img alt="Half-sphere cross-section of a flu virus showing interior and exterior." src="https://images.theconversation.com/files/368065/original/file-20201107-17-l5tdr9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/368065/original/file-20201107-17-l5tdr9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=793&fit=crop&dpr=1 600w, https://images.theconversation.com/files/368065/original/file-20201107-17-l5tdr9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=793&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/368065/original/file-20201107-17-l5tdr9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=793&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/368065/original/file-20201107-17-l5tdr9.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=997&fit=crop&dpr=1 754w, https://images.theconversation.com/files/368065/original/file-20201107-17-l5tdr9.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=997&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/368065/original/file-20201107-17-l5tdr9.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=997&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">3-D illustration of a flu virus. There is no value in taking antibiotics for viral infections.</span>
<span class="attribution"><span class="source">(NIAID)</span>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>But most coughs and colds, sinusitis, influenza and even COVID-19 are viral infections that the immune system will overcome. While some bacteria may be present, they are not the cause, so there is no value in taking an antibiotic. They do not shorten these infections, nor do they reduce their severity, but they could produce adverse effects that only make matters worse. For coughs and colds, it’s better to seek advice from a physician or pharmacist about treatments that reduce fever, aches and pains, and coughs, while the immune system does its job.</p>
<p>As the fall and winter <a href="https://www.cp24.com/news/doctors-brace-for-viral-overload-between-cold-and-flu-season-and-covid-19-1.5070966">respiratory infection season approaches</a>, both prescribers and patients must remember how harmful these drugs can be. Antibiotic use should be minimized, and used only when there is good reason. They must be chosen carefully, and when prescribed, they should be taken for the minimum effective time. So rather than visiting a doctor asking for antibiotics, ask whether one could help, and what other treatments will soothe symptoms and reduce the misery.</p>
<p>Using antibiotics cautiously not only means decreasing the risk of allergic reactions or other harms, but also decreasing the risk of bacterial resistance. That means that when an antibiotic is really needed, the appropriate drug will be safe and effective.</p><img src="https://counter.theconversation.com/content/147547/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>James Dickinson receives funding from Alberta Health to run the Alberta community Influenza surveillance program. </span></em></p><p class="fine-print"><em><span>Ranjani Somayaji has received funding from Cystic Fibrosis Canada, Cystic Fibrosis Foundation, Canadian Institute for Health Research and Alberta Innovates-Health Solutions. </span></em></p><p class="fine-print"><em><span>Samiha Tarek Ah Mohsen does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Resistant bacteria aren’t the only risk posed by overprescribing antibiotics. A more immediate risk is side-effects and reactions, which a new review shows are surprisingly frequent and often severe.James Dickinson, Professor of Family Medicine, University of CalgaryRanjani Somayaji, Assistant Professor in the Department of Medicine, University of CalgarySamiha Tarek Ah Mohsen, Research Assistant at Department of Critical Care Medicine, University of CalgaryLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1473032020-10-07T15:34:30Z2020-10-07T15:34:30ZCan children really stop you catching a bad case of COVID-19?<figure><img src="https://images.theconversation.com/files/361966/original/file-20201006-20-170vra6.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C4528%2C3016&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Don't be fooled. They don't really have super powers.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/six-year-blonde-girl-dressed-like-714497758">nazarovsergey/Shutterstock</a></span></figcaption></figure><p>Having young children in your home may lower your risk of being hospitalised with COVID-19, according to <a href="https://www.medrxiv.org/content/10.1101/2020.09.21.20196428v1">a new study</a> of NHS workers in Scotland.</p>
<p>Children often catch coughs and colds, and this includes seasonal coronaviruses that <a href="https://pubmed.ncbi.nlm.nih.gov/32246136/">cause the common cold</a>. Being of the same virus family, many have assumed the immune response to these common cold coronaviruses may provide some protection from COVID-19. Previous studies, however, have shown that the immune response to seasonal coronaviruses <a href="https://www.nature.com/articles/s41591-020-1083-1">doesn’t last long and that reinfections are common</a>. </p>
<p>The latest study, which has yet to be peer-reviewed, found that adults in households with young children (aged up to 11 years) had a modestly reduced risk of catching SARS-CoV-2 (the coronavirus that causes COVID-19) and a reduced risk of hospitalisation. But adults in households with children aged 12 and older had no reduction in risk compared with adults living without children. </p>
<p>It is important to note that children can be infected with COVID-19, and those that show symptoms are <a href="https://wwwnc.cdc.gov/eid/article/26/10/20-2403_article">just as infectious as adults</a>. Anyone concerned about their child being potentially infectious should follow their <a href="https://www.nhs.uk/conditions/coronavirus-covid-19/symptoms/coronavirus-in-children/#:%7E:text=Symptoms%20of%20coronavirus%20in%20children&text=a%20high%20temperature,or%20taste%20different%20to%20normal">local government guidelines</a>. </p>
<h2>Several limitations</h2>
<p>But there are several important considerations with this study that suggest these findings should be treated with caution. </p>
<p>Several limitations are highlighted by the authors, such as the fact that adults without children were older on average and more likely to have existing health problems when compared with those in a household with children. It is well established that age and other illnesses, such as diabetes and kidney disease, can be a <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7314621/">big factor</a> in how severely ill a person with COVID-19 becomes. The authors acknowledge this. And when taking these factors into account in their statistical model, the child-induced reduced risk effect was diminished – although the risk was still slightly lower than that of adults living without children. </p>
<p>Other factors that need to be considered include the fact that adults with children are more likely to work part-time or reduced hours due to childcare, and this may limit their exposure to COVID-19 through their work. Although the authors took this into consideration when performing their analysis, they concede that they did not have accurate data on the hours worked by the cohort during the study period. </p>
<p>The authors say that if exposure to cold-causing viruses is an important mechanism for protection, childcare providers and teachers might benefit from this exposure. However, before this study is taken as evidence to justify keeping schools open, it should be noted that a big limitation is the period in which data was collected. Data of COVID-19 infections and hospitalisations included for this study were collected between March 1 and July 7, 2020, <a href="https://en.wikipedia.org/wiki/2020_United_Kingdom_education_shutdown">a time during schools were largely closed</a>. </p>
<p>Although many schools were still available for the children of essential workers during the UK lockdown, data to reflect this was not available for this study. So it is impossible to know how many households included in this study had children regularly attending school, or isolating at home, which would affect the households’ potential exposure to COVID-19. </p>
<p>Finally, as the authors rightly point out in their conclusion, despite finding a link between young children in a household and an apparent reduced risk of SARS-CoV-2 infections for the adults, there is no proven mechanism for why this is happening. Many have hypothesised that those exposed to seasonal coronaviruses may have some level of immunity against COVID-19, through something called “cross-protection”, this is <a href="https://www.nature.com/articles/s41467-020-18450-4">yet to be proved</a>. </p>
<figure class="align-center ">
<img alt="Two girls sit on the edge of a bed blowing their nose." src="https://images.theconversation.com/files/361976/original/file-20201006-14-1148668.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/361976/original/file-20201006-14-1148668.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/361976/original/file-20201006-14-1148668.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/361976/original/file-20201006-14-1148668.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/361976/original/file-20201006-14-1148668.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/361976/original/file-20201006-14-1148668.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/361976/original/file-20201006-14-1148668.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Cross-protection is just a theory at this point.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/cold-sick-little-fairhaired-sisters-sitting-1007794207">Yakobchuk Viacheslav/Shutterstock</a></span>
</figcaption>
</figure>
<p>It is always important to remember that correlation does not mean causation – or, as the authors put it, “the observed inverse association may be a chance finding”. It will be interesting to see whether further investigation results in this finding being observed in other populations and whether the cause of this perceived reduced infection risk is determined. Until that link is found, however, this study should be taken with a pinch of salt.</p><img src="https://counter.theconversation.com/content/147303/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Grace C Roberts works at Queen's University, Belfast and receives funding from The Wellcome Trust. </span></em></p>A new study finds a link between having young children at home and a lower risk of catching COVID-19.Grace C Roberts, Research Fellow in Virology, Queen's University BelfastLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1449912020-08-25T12:24:42Z2020-08-25T12:24:42ZA man was reinfected with coronavirus after recovery – what does this mean for immunity?<figure><img src="https://images.theconversation.com/files/354454/original/file-20200824-22-kbunl3.jpg?ixlib=rb-1.1.0&rect=14%2C36%2C4808%2C3176&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Is it possible to get COVID-19 twice?</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/man-wearing-a-face-mask-as-a-precautionary-measure-against-news-photo/1228166500?adppopup=true">May James/AFP via Getty Images</a></span></figcaption></figure><p>A 33-year old man was found to have <a href="https://www.statnews.com/2020/08/24/first-covid-19-reinfection-documented-in-hong-kong-researchers-say/">a second SARS-CoV-2 infection</a> some four-and-a-half months after he was diagnosed with his first, from which he recovered. The man, who showed no symptoms, was diagnosed when he returned to Hong Kong after a trip to Spain. </p>
<p><a href="https://scholar.google.com/citations?user=ubfhdQwAAAAJ&hl=en">I am a virologist</a> with expertise in coronaviruses and enteroviruses, and I’ve been curious about reinfections since the beginning of the pandemic. Because people infected with SARS-CoV-2 can often test positive for the virus for weeks to months, likely due to the sensitivity of the test and <a href="https://doi.org/10.1002/jmv.25952">leftover RNA fragments</a>, the only way to really answer the question of reinfection is by sequencing the viral genome at the time of each infection and looking for differences in the genetic code. </p>
<p>There is no published peer-review report on this man – only a press release from the University of Hong Kong – although reports say the work will be published in the journal <a href="https://academic.oup.com/cid">Clinical Infectious Diseases</a>. Here I address some questions raised by the current news reports. </p>
<h2>Why wasn’t the man immune to reinfection?</h2>
<p>Immunity to endemic coronaviruses – those that cause symptoms of the common cold – <a href="http://doi.org/10.1136/adc.58.7.500">is relatively short-lived</a>, <a href="http://doi.org/10.1017/s0950268800048019">with reinfections occurring</a> even within the same season. So it isn’t completely surprising that reinfection with SARS-CoV-2, the virus that causes COVID-19, might be possible.</p>
<p><a href="https://www.ncbi.nlm.nih.gov/books/NBK279396/">Immunity is complex and involves multiple mechanisms</a> in the body. That includes the generation of antibodies – through what’s known as the adaptive immune response – and through the actions of T-cells, which can help to educate the immune system and to specifically eliminate virus-infected cells. However, researchers around the world are still learning about immunity to this virus and so can’t say for sure, based on this one case, whether reinfection will be a cause for broad concern.</p>
<p>[<em>Get the best of The Conversation, every weekend.</em> <a href="https://theconversation.com/us/newsletters/weekly-highlights-61?utm_source=TCUS&utm_medium=inline-link&utm_campaign=newsletter-text&utm_content=weeklybest">Sign up for our weekly newsletter</a>.]</p>
<h2>How different is the second strain that infected the Hong Kong man?</h2>
<p>“Strain” has a particular definition when referring to viruses. Often a different “strain” is a virus that behaves differently in some way. The coronavirus that infected this man in Europe is likely not a new strain. </p>
<p>A <a href="https://www.statnews.com/2020/08/24/first-covid-19-reinfection-documented-in-hong-kong-researchers-say/">STAT News article</a> reports that the <a href="https://nextstrain.org/ncov/global">genetic make up of the sequenced virus</a> from the patient’s second infection had 24 nucleotides – building blocks of the virus’s RNA genome – that differed from the <a href="https://www.ncbi.nlm.nih.gov/nuccore/1798174254">SARS-CoV-2 isolate</a> that infected him the first time. </p>
<p>SARS-CoV-2 has a genome that is made up of about 30,000 nucleotides, so the virus from the man’s second infection was roughly 0.08% different than the original in genome sequence. That shows that the virus that caused the second infection was new; not a recurrence of the first virus. </p>
<h2>The man was asymptomatic – what does that mean?</h2>
<p>The man wasn’t suffering any of the hallmark COVID-19 symptoms which might mean he had some degree of protective immunity to the second infection because he didn’t seem sick. But this is difficult to prove.</p>
<p>I see three possible explanations. The first is that the immunity he gained from the first infection protected him and allowed for a mild second infection. Another possibility is that the infection was mild because he was presymptomatic, and went on to develop symptoms in the coming days. Finally, sometimes infections with SARS-CoV-2 are asymptomatic – at the moment it is difficult to determine whether this was due to the differences in the virus or in the host.</p>
<h2>What can we say about reinfection based on this one case?</h2>
<p>Only that it seems to be possible after enough time has elapsed. We do not know how likely or often it is to occur.</p>
<h2>Should people who have recovered from COVID-19 still wear a mask?</h2>
<p>As we are still learning about how humans develop immunity to SARS-CoV-2 after infection, my recommendation is for continued masking, hand hygiene and distancing practices, even after recovery from COVID-19, to protect against the potential for reinfection.</p><img src="https://counter.theconversation.com/content/144991/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Megan Culler Freeman is funded by the Pediatric Infectious Diseases Society St. Jude Children's Research Hospital Fellowship in Basic and Translational Research. </span></em></p>Reports describe a Hong Kong man who was reinfected with the coronavirus after returning from Europe. Does that mean he wasn’t immune after the first infection?Megan Culler Freeman, Pediatric Infectious Diseases Fellow, University of PittsburghLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1442952020-08-12T09:51:09Z2020-08-12T09:51:09ZCoronavirus: does the common cold protect you from COVID?<figure><img src="https://images.theconversation.com/files/352237/original/file-20200811-16-1078j78.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C4350%2C2891&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/child-cold-flu-illness-tissue-blowing-195666590">Grzegorz Placzek/Shutterstock</a></span></figcaption></figure><p>An article in <a href="https://science.sciencemag.org/content/early/2020/08/04/science.abd3871.full">Science</a> recently generated a lot of interest by providing a possible explanation of why COVID-19 can be deadly to some yet go virtually unnoticed in others. </p>
<p>Scientists at La Jolla Institute for Immunology in California showed that infection with common cold coronaviruses can generate an immune response that resembles key pieces of the immune response generated by SARS-CoV-2 – the virus that causes COVID-19. This raises the possibility that previous infection with one of the milder coronaviruses could make COVID-19 less severe. But how likely is this? And how does this relate to what we already know about coronaviruses?</p>
<p>A few weeks ago, a <a href="https://www.medrxiv.org/content/10.1101/2020.07.09.20148429v1.full.pdf+html">different article</a> sat at the centre of the SARS-CoV-2 immunity debate. This one showed that the antibody response to SARS-CoV-2 may decline over time. </p>
<p>The findings raised concern that SARS-CoV-2 could infect a person many times and that a vaccine might not generate lasting protection. But the article focused on just one arm of the immune response, the B cells, which produce antibodies that help to clear an infection. </p>
<p>T cells are also key to the immune response against viruses. They play a variety of roles, among them helping B cells to mature into disease-fighting machines. The article by Jose Mateus and colleagues at La Jolla Institute for Immunology is important because it shows that people keep T cells from the milder coronaviruses long enough to potentially interact with a new challenge by SARS-CoV-2 and that those T cells might even recognise SARS-CoV-2 and help to clear the infection.</p>
<figure class="align-center ">
<img alt="Antibodies attacking a coronavirus." src="https://images.theconversation.com/files/352252/original/file-20200811-21-r4e4qc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/352252/original/file-20200811-21-r4e4qc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/352252/original/file-20200811-21-r4e4qc.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/352252/original/file-20200811-21-r4e4qc.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/352252/original/file-20200811-21-r4e4qc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/352252/original/file-20200811-21-r4e4qc.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/352252/original/file-20200811-21-r4e4qc.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Antibodies latching onto a coronavirus to neutralise it.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-illustration/antibodies-attacking-sarscov2-virus-conceptual-3d-1700617951">Kateryna Kon/Shutterstock</a></span>
</figcaption>
</figure>
<h2>The case for cross-immunity</h2>
<p>For epidemiologists, the evidence of waning immunity and cross-immunity didn’t come as a surprise. <a href="https://www.ncbi.nlm.nih.gov/">A study from 1990</a> showed that soldiers infected with one of the milder coronaviruses didn’t retain immunity for much longer than a year. Also, the boom-bust cycle that the milder coronaviruses undergo from year to year <a href="https://science.sciencemag.org/content/368/6493/860/tab-article-info">can be explained</a> by a mix of waning immunity and cross-immunity. </p>
<p>The milder coronaviruses can generate similar antibodies to the ones that are generated by the coronaviruses that <a href="https://www.sciencedirect.com/science/article/pii/S0163445313000716?casa_token=1JhpcW0diDcAAAAA:LArOJgNTKdoTLUEHLKef9hwsXb3McXIKE6VRowGIpddTRYEFVng5v-ujggY2_MyAzFHQ8AsyQQ">cause Sars and Mers</a>. These antibodies are so similar that they <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2095096/">nearly tricked</a> a British Columbia care facility into thinking they had an outbreak of Sars after the Sars epidemic had been declared over. In fact, the outbreak was caused by OC43, one of the coronaviruses that causes the common cold. </p>
<p>Nevertheless, infections that generate structurally similar antibodies don’t necessarily provide cross-protection in a medically meaningful way.</p>
<h2>We’re still just not sure</h2>
<p>Evidence for cross-protection between all but the most closely related coronaviruses is scant. </p>
<p>It is difficult to say whether the milder coronaviruses protect against SARS-CoV-2 partly because we have done so little surveillance on them. Ideally, we would be able to look at historical data to identify which communities experienced major outbreaks of each milder coronavirus strain over the past few years and then see if there is a link with less severe COVID-19 cases. </p>
<p>Challenge studies, in which a person is intentionally infected with a milder coronavirus strain and then exposed to SARS-CoV-2, could also address the question but are dangerous and ethically fraught. For now, all we can say is that the possibility that the common coronaviruses might protect against SARS-CoV-2 remains just that – a possibility. Indeed, Mateus and colleagues describe this theory as “highly speculative”.</p><img src="https://counter.theconversation.com/content/144295/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Stephen Kissler does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Some people who have never had COVID-19 have the antibodies to fight it – possibly from an earlier infection with a different coronavirus.Stephen Kissler, Postdoctoral Researcher, Immunology and Infectious Diseases, Harvard UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1372092020-05-13T12:09:29Z2020-05-13T12:09:29ZCoronavirus vaccine: reasons to be optimistic<p>The first coronaviruses known to infect humans were <a href="https://www.cdc.gov/coronavirus/types.html">discovered more than half a century ago</a> – so why are there no vaccines against these viruses? Should we be optimistic that an effective vaccine will be developed now?</p>
<p>SARS-CoV-2, the recently discovered coronavirus that causes COVID-19, is similar enough to other coronaviruses, so scientists make predictions about how our immune system might deal with it. But its novelty warrants its own careful study. Similar to Sars and Mers that cause severe acute respiratory syndrome, the novel coronavirus has emerged from animals and can cause damage to the <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7102538/">lungs</a> and sometimes <a href="https://www.sciencemag.org/news/2020/04/how-does-coronavirus-kill-clinicians-trace-ferocious-rampage-through-body-brain-toes#">other organs</a>.</p>
<p>Why don’t we have a vaccine against other human coronaviruses? The emergence of Sars and Mers, in 2002 and 2012 respectively, were either quashed relatively quickly or affected small numbers of people. Despite the interest from keen virologists, there was no economic incentive to develop a vaccine for these diseases as they posed a small threat at the time. Virologists with an interest in coronaviruses were struggling to secure funding for their research. </p>
<p>In contrast, COVID-19 has caused huge disruption around the world. As a result, <a href="https://www.nature.com/articles/d41586-020-01221-y">at least 90</a> vaccines are under development, with <a href="https://www.who.int/who-documents-detail/draft-landscape-of-covid-19-candidate-vaccines">some already in human trials</a>. </p>
<h2>How a vaccine works</h2>
<p>A vaccine gives our body a harmless flavour of the virus, alerting the immune response to generate antibodies and/or cellular immunity (T cells) ready to fight the infection. The idea is that we can then deploy a ready-made defence system next time we encounter the virus, and this spares us from severe symptoms. We know that most people who have recovered from COVID-19 <a href="https://www.ncbi.nlm.nih.gov/pubmed/32350462">have detectable antibodies</a> in their blood. </p>
<p>We don’t know if these antibodies are fully protective, but a vaccine still has the potential to elicit powerful neutralising antibodies and scientists will evaluate these following vaccination. Researchers will also look for potent T cell responses in the blood of vaccinated people. These measurements will help scientists predict the efficacy of the vaccine, and will be available before a vaccine is approved. </p>
<p>The best way to evaluate a vaccine, of course, is to judge how well it protects people from infection. But exposing vulnerable groups to the virus is far too risky, so most vaccines will be tested in younger people with no underlying health problems. There are <a href="https://academic.oup.com/jid/article/221/11/1752/5814216">ethical considerations</a> for deliberately infecting a healthy person with a potentially dangerous virus for a vaccine trial, and these need to be considered carefully. </p>
<p>In the course of a pandemic, a vaccinated volunteer may become infected with the novel coronavirus, especially if they are a healthcare worker. It will take time to gather data on protection following infection and compare them to people that received a placebo vaccine. </p>
<h2>Vaccine challenges</h2>
<p>The ideal vaccine should protect everyone and cause lifelong defences with a single dose. It would be quick to produce, affordable, easy to administer (nasal or oral administration) and wouldn’t need refrigeration, so non-specialists can distribute it to hard-to-reach parts of the world. In reality, we don’t fully understand how to produce a vaccine that induces long-lived protective immunity for different viruses. For some infections, we need to administer booster vaccinations. </p>
<p>Ageing comes with a tired immune system that struggles to respond to vaccination, and this is also the case for people with weakened immune systems, so it is difficult to protect the most vulnerable. Therefore, vaccination programmes that protect over 80% of the population can reduce the incidence of virus spreading and protect the vulnerable by proxy, through herd immunity. Currently, <a href="https://www.ecdc.europa.eu/en/geographical-distribution-2019-ncov-cases">the percentage of people who may have had COVID-19 in different parts of the world varies</a>, but this is hard to estimate because of test availability.</p>
<p>Scientists test and confirm a vaccine’s safety before it is approved. We appreciate that in some viral infections, <a href="https://stm.sciencemag.org/content/5/200/200ra114?ijkey=3fd5153d1fd32d5c17c6395632928368e658b597&keytype2=tf_ipsecsha">existing antibodies from an earlier infection with the same type of virus</a> can cause more severe disease. However, there is no strong evidence for any adverse effects of antibodies for SARS-CoV-2 infection.</p>
<h2>Within reach</h2>
<p>Here are some reasons to be optimistic. One, this virus can be cured. Unlike some viruses such as HIV that embed their genome in our own and make fresh copies of themselves after immune elimination, we know that SARS-CoV-2 is <a href="https://www.ncbi.nlm.nih.gov/pubmed/32150748">unable to persist</a> in this way. </p>
<p>Two, most infected patients <a href="https://www.ncbi.nlm.nih.gov/pubmed/32350462">develop antibodies</a> and there is evidence of virus-specific <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2683413/">T cell responses</a>. Although we don’t know if these responses are protective yet, these are precisely the responses that can lead to immunological memory, the cornerstone of vaccination. Vaccine products will be refined and enriched to induce more potent immune responses than natural infection. </p>
<p>Three, coronaviruses mutate <a href="https://www.livescience.com/coronavirus-mutation-rate.html">slower</a> than viruses such as influenza, and we know from Sars and Mers that antibodies can <a href="https://www.medscape.com/viewarticle/870592_1">persist</a> for at least one to two years following recovery. This is good news for an effective vaccine that may not require updating for quite some time. </p>
<p>There are more reasons to be upbeat. Scientists are <a href="https://www.nature.com/articles/d41586-020-01221-y">testing several approaches</a> so there is a higher probability of success, and pharmaceutical companies have been engaged early, scaling up production and working out logistics for distribution even before there is evidence the vaccine will work. This is worth the investment because resources can be quickly repurposed for the most promising vaccines following the first clinical trials. </p>
<p>A coronavirus vaccine is within our reach, and it is our best hope to stem transmission and generate herd immunity to protect the most vulnerable. Taking away its hosts for replication, we can eradicate this virus from the human population just as vaccination previously eradicated smallpox.</p><img src="https://counter.theconversation.com/content/137209/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Zania Stamataki receives funding from the Medical Research Council, the Medical Research Foundation, the Birmingham Children's Hospital Research Foundation and the Canadian Government. Dr Stamataki collaborates with pharmaceutical companies on projects unrelated to vaccine research. </span></em></p>We don’t have vaccines for the Sars, Mers or the common cold. But that doesn’t mean scientists won’t crack it this time.Zania Stamataki, Senior Lecturer in Viral Immunology, University of BirminghamLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1355062020-04-15T10:33:45Z2020-04-15T10:33:45ZCoronaviruses – a brief history<figure><img src="https://images.theconversation.com/files/327667/original/file-20200414-117567-1rtiuw1.jpg?ixlib=rb-1.1.0&rect=0%2C71%2C5332%2C3472&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">
</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/young-funny-woman-sneezing-spray-small-1126125494">Master1305/Shutterstock</a></span></figcaption></figure><p>Most of us will be infected with a coronavirus at least once in our life. This might be a worrying fact for many people, especially those who have only heard of one coronavirus, SARS-CoV-2, the cause of the disease known as COVID-19. </p>
<p>There is much more to coronaviruses than SARS-CoV-2. Coronaviruses are actually a family of hundreds of viruses. Most of these infect animals such as bats, chickens, camels and cats. Occasionally, viruses that infect one species can mutate in such a way that allows them to start infecting another species. This is called “cross-species transmission” or “spillover”. </p>
<p>The first coronavirus was <a href="https://link.springer.com/chapter/10.1007/978-3-642-65775-7_3">discovered in chickens</a> in the 1930s. It was a few decades until the <a href="https://journals.lww.com/pidj/Fulltext/2005/11001/History_and_Recent_Advances_in_Coronavirus.12.aspx">first human coronaviruses were identified</a> in the 1960s. To date, seven coronaviruses have the ability to cause disease in humans. Four are endemic (regularly found among particular people or in a certain area) and usually cause mild disease, but three can cause much more serious and even fatal disease. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/327664/original/file-20200414-117587-d00aqy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/327664/original/file-20200414-117587-d00aqy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/327664/original/file-20200414-117587-d00aqy.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/327664/original/file-20200414-117587-d00aqy.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/327664/original/file-20200414-117587-d00aqy.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/327664/original/file-20200414-117587-d00aqy.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/327664/original/file-20200414-117587-d00aqy.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">The first coronavirus discovered was in chickens.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/bird-flu-134912495">Pieter/Shutterstock</a></span>
</figcaption>
</figure>
<h2>Common cold</h2>
<p>Coronaviruses can be found all over the world and are responsible for about <a href="https://journals.lww.com/pidj/Fulltext/2005/11001/History_and_Recent_Advances_in_Coronavirus.12.aspx">10-15% of common colds</a>, mostly during the winter. The coronaviruses that cause mild to moderate disease in humans are called: 229E, OC43, NL63 and HKU1. </p>
<p>The first coronaviruses discovered that are able to infect humans are 229E and OC43. Both of these viruses usually result in the common cold and rarely cause severe disease on their own. They are often detected at the same time as other respiratory infections. When several viruses, or viruses and bacteria, are found in patients this is called co-infection and can result in more severe disease.</p>
<p>In 2004, NL63 was detected <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2918871/">for the first time</a> in a baby suffering from bronchiolitis (a lower respiratory tract infection) in the Netherlands. This virus has probably been around for hundreds of years, we just hadn’t found it until then. A year later, in Hong Kong, another coronavirus was found – this time in an elderly patient with pneumonia. It was later named HKU1 and has been found to be present <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1489438/">in populations around the world</a>. </p>
<h2>Deadlier strains</h2>
<p>But not all coronaviruses cause mild disease. Sars (severe acute respiratory syndrome) caused by <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3322938/">SARS-CoV was first detected in November 2002</a>. The cause of this outbreak wasn’t confirmed until 2003 when the genome of the virus was identified by Canada’s National Microbiology Laboratory. Sars bears many similarities to the current pandemic of COVID-19. Older people were much more likely to suffer severe disease and symptoms included fever, cough, muscle pain and sore throat. But there was a much greater chance of dying if you had Sars. From 2002 until the last reported case in 2014, <a href="https://www.who.int/csr/sars/country/table2004_04_21/en/">774 people died</a>.</p>
<p>A decade later, in 2012, there was another outbreak involving a newly identified coronavirus: MERS-CoV. The first case of Middle East respiratory syndrome (Mers) <a href="https://web.archive.org/web/20131104184337/http://www.virology-bonn.de/fileadmin/user_upload/_temp_/Zaki_et_al.pdf">occurred in Saudi Arabia</a>. There were two further Mers outbreaks: <a href="https://www.who.int/csr/don/25-october-2015-mers-korea/en/">South Korea in 2015</a> and <a href="http://www.emro.who.int/pandemic-epidemic-diseases/news/infectious-disease-outbreaks-reported-in-the-eastern-mediterranean-region-in-2018.html">Saudi Arabia in 2018</a>. There are a handful of Mers cases every year, but the outbreaks are usually well contained. </p>
<p>So why did Sars or Mers not result in pandemics? The R0 of both Sars and SARS-CoV-2 is about <a href="https://www.ijidonline.com/article/S1201-9712(20)30123-5/fulltext">two or three</a> (although some more recent estimates of the R0 for SARS-CoV-2 are <a href="https://wwwnc.cdc.gov/eid/article/26/7/20-0282_article">around five</a>), meaning that every infected person is likely to infect two or three other people. The symptoms of Sars were more severe, so it was much easier to identify and isolate patients.</p>
<p>The R0 of <a href="https://wwwnc.cdc.gov/eid/article/26/2/19-0697_article">Mers is below one</a>. It is not very contagious. Most of the cases have been linked to close contact with infected camels or very close contact with an already infected person. </p>
<p>One of the main challenges in containing the SARS-CoV-2 outbreak is that symptoms can be very mild – some people may not even show any symptoms at all – but can still infect other people. SARS-CoV-2 is not as deadly as either Sars or Mers, but because it can spread undetected, the numbers of people it will infect and the numbers that will die will be higher than any coronavirus we have ever encountered. So please, stay at home.</p><img src="https://counter.theconversation.com/content/135506/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Lindsay Broadbent receives funding from Wellcome Trust. </span></em></p>Ever heard of 229E, OC43, NL63 and HKU1?Lindsay Broadbent, Research Fellow, School of Medicine, Dentistry and Biomedical Sciences, Queen's University BelfastLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1346232020-03-27T15:20:54Z2020-03-27T15:20:54ZIs the loss of your sense of smell and taste an early sign of COVID-19?<figure><img src="https://images.theconversation.com/files/323427/original/file-20200326-132980-k90ydu.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Can you smell this?</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/photo/young-woman-smelling-roasted-coffee-beans-royalty-free-image/1025627764?adppopup=true">Getty Images</a></span></figcaption></figure><p><em>Doctors from around the world are reporting cases of COVID-19 patients who have lost their sense of smell, known as anosmia, or taste, known as ageusia. The director of the University of Florida’s Center for Smell and Taste and the co-director of the UF Health Smell Disorders Program answer questions about this emerging trend.</em></p>
<p><strong>Is the loss of smell an early sign of COVID-19?</strong></p>
<p>Loss of smell <a href="https://doi.org/10.1159/000093758">occurs with the common cold</a> and other viral infections of the nose and throat. Anecdotal reports suggest the loss of smell may be <a href="https://www.npr.org/sections/goatsandsoda/2020/03/26/821582951/is-loss-of-smell-and-taste-a-symptom-of-covid-19-doctors-want-to-find-out">one of the first symptoms</a> of COVID-19. Doctors around the world are reporting that <a href="https://www.livescience.com/covid-19-symptoms-loss-smell-taste.html">up to 70% of patients who test positive for the coronavirus disease COVID-19</a> – even those without fever, cough or other typical symptoms of the disease – are experiencing anosmia, a loss of smell, or ageusia, a loss of taste. A <a href="https://academic.oup.com/cid/advance-article/doi/10.1093/cid/ciaa330/5811989">new study</a> just published found that 20 of 59 patients (ages 50-74) interviewed in Italy reported a smell or taste loss. More research is needed to understand this link, but it may provide a low-cost, practical indicator of which people should self-isolate or get further testing, depending on the symptom severity and testing availability. </p>
<p><strong>What are anosmia and ageusia?</strong></p>
<p>The body’s chemical senses include smell, used to detect volatile odors, and taste, which recognizes food compounds like sugars, salts and acids. A number of chemosensory disorders result in the diminishment, distortion or complete loss of smell or taste functions. For example, anosmia is the complete loss or absence of smell, while hyposmia is a reduced ability to smell. Similarly, ageusia is an absence of taste. </p>
<p>Approximately <a href="https://doi.org/10.1159/000093758">13% of people</a> over 40 years old have a significant impairment of their sense of smell. These numbers are lower for younger people, but significantly higher for the elderly. By contrast, taste loss is much less prevalent, and often results from physical damage to the taste nerves. Even so, both smell and taste disorders are quite common and can have <a href="https://www.nidcd.nih.gov/health/taste-smell">major negative impacts</a> on the health and quality of life of the millions affected.</p>
<p>According to <a href="https://time.com/5809037/coronavirus-sense-of-smell-taste/">news reports</a>, many of the COVID-19 patients reporting a chemosensory loss describe a loss of taste. However, it is more likely that smell loss accounts for this symptom. When we eat or drink, the brain combines our perceptions of taste from the mouth with what is known as retronasal olfaction – that is, the perception of smell that comes from odors leaving the mouth and entering the nose through the connecting passage in the throat – into what is specifically called flavor. Patients who have experienced anosmia or severe hyposmia may describe a loss of taste but are still able to detect sugar, salt or acid on the tongue. What they have lost is the contribution of smell to their perception of flavor. We would predict that in most cases, the taste loss reported by COVID-19 patients is likely due to a reduced or absent ability to smell.</p>
<p><strong>Why could the coronavirus cause anosmia?</strong></p>
<p>Loss of smell can result from many <a href="https://jamanetwork.com/journals/jamaotolaryngology/article-abstract/619670">diverse causes</a> such as head trauma, nasal polyps, chronic allergies, toxin exposure and neurodegenerative disease. </p>
<p>One of the most common causes of anosmia and hyposmia are viruses that produce upper respiratory infections, often referred to as the “common cold.” </p>
<p>Viruses could impact smell function in any of several ways. They could attack various cells in the nasal tissue, inducing local inflammation and disrupting odor detection. The virus could directly disable or damage the sensory cells in the nose that detect odors. Another possibility is that viruses <a href="https://onlinelibrary.wiley.com/doi/full/10.1002/path.4461">could follow the olfactory nerve’s pathway</a> through the skull and into the brain, where they could do additional damage. Whether this coronavirus wreaks havoc on our sense of smell by killing olfactory sensory neurons, by disrupting their function or by otherwise impacting nasal olfactory tissues remains unknown, but will certainly be an important area of investigation.</p>
<p><strong>Could anosmia serve as an early indicator for COVID-19 disease?</strong></p>
<p>The <a href="https://www.forbes.com/sites/judystone/2020/03/20/theres-an-unexpected-loss-of-smell-and-taste-in-coronavirus-patients/#7d5ace5d5101">doctor and patient anecdotes</a> reported recently describe a high incidence of anosmia in COVID-19 patients, including many without other symptoms. Thus, smell testing could be a useful tool to identify people who may be infected with COVID-19. Indeed, some otolaryngologists, doctors who treat diseases of the ear, nose and throat, in the <a href="https://www.entuk.org/sites/default/files/files/Loss%20of%20sense%20of%20smell%20as%20marker%20of%20COVID.pdf">United Kingdom</a> and <a href="https://www.entnet.org/content/aao-hns-anosmia-hyposmia-and-dysgeusia-symptoms-coronavirus-disease">United States</a> have recommended that individuals who experience a sudden loss of smell or taste should self-isolate for 14 days, and that smell testing should be integrated into COVID-19 screening protocols.</p>
<p>But do the facts bear this out? For example, <a href="https://onlinelibrary.wiley.com/doi/full/10.1002/alr.21869">one small study</a> of 59 people found that 60% of patients with upper respiratory infections not related to COVID-19 had a significant reduction in their ability to smell. This might suggest that the prevalence of smell loss associated with COVID-19 is no higher than that typically experienced with the common cold. Unfortunately, smell testing is rarely done as part of a normal doctor’s visit, so the data to resolve this is lacking. Furthermore, self-reporting of smell function can be inaccurate. It is thus critical to conduct controlled scientific studies to assess whether smell disorders such as anosmia are an indicator of a COVID-19 infection.</p>
<p>It will take time to conduct those studies. In the meantime, what should you do if you experience sudden smell loss? The <a href="https://www.entuk.org/sites/default/files/files/Loss%20of%20sense%20of%20smell%20as%20marker%20of%20COVID.pdf">advice</a> from ENT UK, a professional group which represents ear, nose and throat surgeons, and the British Rhinological Society seems prudent. Self-isolate, and contact your physician for recommendations of next steps. Smell testing as part of a typical COVID-19 screen, as <a href="https://www.entnet.org/content/aao-hns-anosmia-hyposmia-and-dysgeusia-symptoms-coronavirus-disease">recommended</a> by the American Academy of Otolaryngologists, also makes sense, even if the test is not diagnostic for COVID-19 in and of itself. Simple <a href="https://www.sciencedirect.com/science/article/pii/0031938484902695?via%3Dihub">scratch-and-sniff smell tests</a> could be sent to patients to take in their home and report via secure communications, minimizing coronavirus exposure of overburdened health care providers. Along with body temperature readings and a patient history, smell testing could allow physicians to make better choices about who to prioritize for self-isolation or more specific COVID-19 testing.</p>
<p>[<em>You need to understand the coronavirus pandemic, and we can help.</em> <a href="https://theconversation.com/us/newsletters?utm_source=TCUS&utm_medium=inline-link&utm_campaign=newsletter-text&utm_content=upper-coronavirus-help">Read our newsletter</a>.]</p><img src="https://counter.theconversation.com/content/134623/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Steven D. Munger receives funding from the National Institute on Deafness and Communication Disorders and the U.S. Department of Agriculture.</span></em></p><p class="fine-print"><em><span>Jeb Justice is a consultant to Intersect ENT and Medtronic, INC. </span></em></p>Patients who later test positive for COVID-19 are reporting early loss of smell and taste. Researchers are now trying to understand if this could be an early sign of the disease.Steven D. Munger, Director, Center for Smell and Taste; Co-Director, UF Health Smell Disorders Program; Professor of Pharmacology and Therapeutics, University of FloridaJeb M. Justice, Associate Professor, Chief of the Division of Rhinology and Skull Base Surgery, Co-Director UF Health Smell Disorders Program, University of FloridaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1262412019-12-23T11:49:10Z2019-12-23T11:49:10ZCan you die from a common cold?<figure><img src="https://images.theconversation.com/files/301348/original/file-20191112-178490-y3xwed.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">shutterstock</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/download/confirm/742728895?src=ff9b051b-8937-470d-9500-ab859274f58c-1-11&size=medium_jpg">Estrada Anton/Shutterstock</a></span></figcaption></figure><p>Most people know that the flu can kill. Indeed, the so-called Spanish flu killed 50 million people in 1918 – more than were killed in the <a href="https://www.ncbi.nlm.nih.gov/pubmed/31341062">first world war</a>. But what about the common cold? Can you really catch your death? </p>
<p>The cold is a collection of symptoms – coughing, sneezing, a runny nose, tiredness and perhaps a fever – rather than a defined disease. Although it shares a lot with the initial symptoms with the flu, it’s a very different infection.</p>
<p>Rhinovirus causes about half of all colds, but other viruses can cause one or more of the symptoms of a cold, including adenovirus, influenza virus, respiratory syncytial virus and parainfluenza virus.</p>
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<img alt="" src="https://images.theconversation.com/files/306116/original/file-20191210-95111-11qgn7s.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/306116/original/file-20191210-95111-11qgn7s.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/306116/original/file-20191210-95111-11qgn7s.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/306116/original/file-20191210-95111-11qgn7s.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/306116/original/file-20191210-95111-11qgn7s.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/306116/original/file-20191210-95111-11qgn7s.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/306116/original/file-20191210-95111-11qgn7s.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
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<span class="caption">The rhinovirus causes about half of all colds.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-illustration/rhinoviruses-predominant-cause-common-cold-3d-752410657">Maryna Olyak/Shutterstock</a></span>
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<p>The common cold is normally a mild illness that resolves without treatment in a few days. And because of its mild nature, most cases are self-diagnosed. However, infection with rhinovirus or one of the other viruses responsible for common cold symptoms can be serious in some people. Complications from a cold can cause serious illnesses and, yes, even death – particularly in people who have a weak immune system.</p>
<p>For example, <a href="https://www.ncbi.nlm.nih.gov/pubmed/10530441">studies have shown</a> that patients who have undergone a bone marrow transplant can have a higher likelihood of developing a serious respiratory infection. While rhinovirus is not thought to be the main cause of this, other viruses that are associated with symptoms of the common cold, such as RSV, adenovirus and parainfluenza virus, are. </p>
<p>There is, of course, more than one way for someone to become very sick after infection with a respiratory virus. Some viruses, such as adenovirus, can also cause symptoms throughout the body, including the gastrointestinal tract, the urinary tract and the liver.</p>
<p>Other viruses, like the influenza virus, can themselves potentially cause severe inflammation in the lungs, but they can also lead to particularly serious conditions, such as <a href="https://www.webmd.com/lung/bacterial-pneumonia#1">bacterial pneumonia</a>. </p>
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<strong>
Read more:
<a href="https://theconversation.com/we-have-a-good-chance-of-curing-the-common-cold-in-next-ten-years-a-scientist-explains-96478">We have a good chance of curing the common cold in next ten years – a scientist explains</a>
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<p>A virus-induced bacterial infection is one way a cold or flu virus can lead to death. While the exact mechanisms of how bacterial infections can be primed by viral infection are still being investigated, a possible way it can occur is through increased bacterial attachment to cells of the lung. For example, rhinovirus has been shown to increase the presence of a receptor called PAF-r in lung cells. This can allow bacteria, such as <em>Streptococcus pneumoniae</em>, to bind more effectively to the cells, <a href="https://www.ncbi.nlm.nih.gov/pubmed/14673774">increasing the likelihood</a> of it leading to a severe condition like pneumonia.</p>
<h2>Higher risk in some people</h2>
<p>Unfortunately, a cold can also have more severe symptoms in the very young and the very old. Older people are more likely to develop a more serious infection compared with adults or older children. And people who smoke – or who are exposed to second-hand smoke – are also more likely to get a cold and have more severe symptoms. </p>
<p>Another group of people who are more severely affected by infection with cold-causing viruses are people with an existing lung condition. They can include people with asthma, cystic fibrosis or chronic obstructive pulmonary disease (COPD). Infection with a virus that causes inflammation of the airways can make breathing much harder. People with COPD who catch a mild cold virus are also at risk of developing a bacterial infection. </p>
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Read more:
<a href="https://theconversation.com/your-lungs-are-full-of-microorganisms-and-thats-a-good-thing-57228">Your lungs are full of microorganisms ... and that's a good thing</a>
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<p>While the bacterial infection in these patients can be treated with antibiotics, there is no effective antiviral treatment against all types of rhinovirus. For other respiratory viruses, such as influenza, there is an effective vaccine that can help protect vulnerable people from the flu virus, including asthmatics, the very young and the very old. </p>
<p>There is not one single element that dictates how severe an infection with a cold virus will be, but there are many conditions or factors that can raise a red flag.</p>
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Read more:
<a href="https://theconversation.com/flu-jab-for-asthmatics-avoiding-the-flu-vaccine-could-be-a-fatal-mistake-121347">Flu jab: for asthmatics, avoiding the flu vaccine could be a fatal mistake</a>
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<p>One of the best ways to avoid catching a cold is to wash your hands properly. This can prevent the spread of many different infections, not just the viruses that cause the common cold. And everyone, not just those classed as vulnerable, should get the flu jab. For viral infections, prevention is key.</p><img src="https://counter.theconversation.com/content/126241/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Peter Barlow is currently in receipt of funding from the Medical Research Council, the BBSRC and the Daphne Jackson Trust for projects unrelated to this piece. He has previously received funding from the Chief Scientist Office (Scotland) on a project investigating host defence peptides as therapeutics for rhinovirus infection (ETM/389). He is currently Chair of the British Society for Immunology Inflammation Affinity Group.</span></em></p>You’ll catch your death!Peter Barlow, Professor of Immunology and Infection and Head of Research of the School of Applied Sciences, Edinburgh Napier UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/964782018-06-18T15:06:33Z2018-06-18T15:06:33ZWe have a good chance of curing the common cold in next ten years – a scientist explains<figure><img src="https://images.theconversation.com/files/223555/original/file-20180618-85830-1bqx90h.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Snot funny. </span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/paper-tissue-box-used-tissues-over-26128165?src=s4ee3MwijqcXGu_E2EzZkA-1-10">Pryzmat</a></span></figcaption></figure><p>Some people get barely any symptoms and recover rapidly. Others end up confined to bed, surrounded by used tissues. For those with compromised immune systems or respiratory conditions, it can even be life-threatening. We’d all dearly like to see a cure for the common cold, but it never quite seems to arrive. So what’s the hold up – and will it be over soon?</p>
<p>The common cold is actually a catch-all term for a variety of viral infections that cause sore throats, headaches, coughs and sneezes. Men <a href="https://www.theguardian.com/lifeandstyle/2017/dec/11/stop-accusing-men-of-overreacting-man-flu-really-does-exist-claims-doctor">may be</a> predisposed to suffer more from these symptoms, though the existence of “man flu” is a subject for another day. </p>
<p>The most common variety of common cold is rhinovirus, which accounts for <a href="https://www.ncbi.nlm.nih.gov/pubmed/27251607">around 50%</a> of all infections (it gets its name not directly from the wild animal but because “rhino” is Greek for “nose”). Kids <a href="https://www.ncbi.nlm.nih.gov/pubmed/9207716">are usually</a> infected between eight and 12 times a year, adults more like two or three times. Other viruses that we also think of as the common cold include adenovirus, respiratory syncytial virus and influenza virus. But for most scientists in this field, cracking rhinovirus is the number one challenge. </p>
<h2>Shifting a rhino</h2>
<p>Rhinovirus is not just one organism. There are currently over 160 different strains, and it’s extremely difficult to make a vaccine or antiviral that will cover all of them. </p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/223545/original/file-20180618-85825-xjihpx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/223545/original/file-20180618-85825-xjihpx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/223545/original/file-20180618-85825-xjihpx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=900&fit=crop&dpr=1 600w, https://images.theconversation.com/files/223545/original/file-20180618-85825-xjihpx.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=900&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/223545/original/file-20180618-85825-xjihpx.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=900&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/223545/original/file-20180618-85825-xjihpx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=1130&fit=crop&dpr=1 754w, https://images.theconversation.com/files/223545/original/file-20180618-85825-xjihpx.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=1130&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/223545/original/file-20180618-85825-xjihpx.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=1130&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">Who you calling a virus?</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/download/confirm/337062761?src=eX550lh23C_7yb3Yzr2OzQ-1-3&size=medium_jpg">Johan Swanepoel</a></span>
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<p>There are only around 90 to 95 antivirals in total – far fewer than our arsenal of antibiotics – and none have been licensed for use against rhinovirus. A few show some activity against certain strains, but are ineffective against others. The chances of an antiviral emerging that can directly kill all strains look slim at present. </p>
<p>A number of groups across the globe are working hard to find alternative solutions – I’ve just co-authored a <a href="https://www.futuremedicine.com/doi/10.2217/fvl-2018-0016">review paper</a> that documents the latest progress. Many groups are trying to manipulate the proteins inside the cells of the host, since they are vital for virus replication. This may be an incredibly effective way to halt the virus spreading to other cells in the body. </p>
<p>One exciting prospect <a href="http://www.nature.com/articles/s41557-018-0039-2">emerged</a> very recently from Imperial College, London: a synthetic compound that targets enzymes in the cells that the virus infects, known as NMT1 and NMT2, and prevents them from being used during viral replication. Another team in Canada <a href="https://www.ncbi.nlm.nih.gov/pubmed/23726345">is working</a> on compounds that can inhibit a different class of human enzymes, called PI4KB, that are also required for the virus to replicate. </p>
<p>Several teams in the US, as well as in the Pirbright Institute in the south of England, are working on a different approach. They have been trying to halt the infection using particular antibodies, known as <a href="http://www.virology.ws/2009/07/24/virus-neutralization-by-antibodies/">neutralising antibodies</a>, which work against different proteins within the virus. Yet the number and diversity of rhinoviruses around the world has meant that a universal antibody has yet to be developed.</p>
<h2>Pep talk</h2>
<p>My research group is trying to solve the problem from yet another angle. We are working on a family of molecules known as host defence peptides or antimicrobial peptides, which are a key part of people’s frontline immune response against viruses. As well as humans, they are found in many other mammals, plants and insects. </p>
<p>We and others have shown that these peptides can kill a wide range of bacteria, fungi and viruses. For example, one of our studies <a href="https://www.ncbi.nlm.nih.gov/pubmed/22031815">showed that</a> a peptide found in the human immune system, known as cathelicidin, was incredibly effective at killing the influenza virus at a level comparable with current anti-influenza drugs. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/223556/original/file-20180618-85819-yl56aq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/223556/original/file-20180618-85819-yl56aq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/223556/original/file-20180618-85819-yl56aq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/223556/original/file-20180618-85819-yl56aq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/223556/original/file-20180618-85819-yl56aq.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/223556/original/file-20180618-85819-yl56aq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/223556/original/file-20180618-85819-yl56aq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/223556/original/file-20180618-85819-yl56aq.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">Your friendly neighbourhood cathelidicin.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-illustration/cathelicidin-which-serves-critical-role-mammalian-576972064?src=fOlaNYQff_lwd80-BSEFyA-1-0">Ibreakstock</a></span>
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<p>More recently, we <a href="https://www.ncbi.nlm.nih.gov/pubmed/28764966">investigated</a> whether this same human cathelicidin peptide could kill rhinovirus and were excited to find that it did. We found that cathelicidins from other animals such as pigs were very effective at killing this human virus, too – raising the prospect that peptides from the immune systems of other mammals could be employed to fight this infection. </p>
<p>This is just the first step in a long path, however. Now we hope to modify these peptides to make them more stable and effective, not only against rhinovirus and influenza but also against other varieties of cold virus. And so far all our work has only been at the lab bench, and against only one common strain of rhinovirus: the next step will be to progress into animal and finally human clinical trials. </p>
<p>Each of the three described approaches is at a similar stage of development. It is very difficult to put a timeframe on these things, but they are all probably about five to ten years from potentially producing a viable treatment. </p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/223635/original/file-20180618-85863-1xattpi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/223635/original/file-20180618-85863-1xattpi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/223635/original/file-20180618-85863-1xattpi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=735&fit=crop&dpr=1 600w, https://images.theconversation.com/files/223635/original/file-20180618-85863-1xattpi.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=735&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/223635/original/file-20180618-85863-1xattpi.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=735&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/223635/original/file-20180618-85863-1xattpi.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=924&fit=crop&dpr=1 754w, https://images.theconversation.com/files/223635/original/file-20180618-85863-1xattpi.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=924&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/223635/original/file-20180618-85863-1xattpi.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=924&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
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<span class="caption">Hot, hot, hot.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/hot-drink-honey-lemon-wrapped-scarf-481098646?src=aNnHtTgtYsL-pGI_LetL3A-1-88">Inventbbart</a></span>
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<p>Yet when the day finally comes that science cracks the common cold, we will need to be extremely cautious. It is worth drawing a parallel with antibiotics: just as <a href="https://theconversation.com/bacterias-secret-weapons-in-defeating-antibiotics-discovered-87272">antibiotic resistance</a> is an increasingly serious problem, the same thing can happen with viral treatments. </p>
<p>It would therefore be unwise to start doling out the “cold cure” to everyone who has a cold. Instead, I would suggest keeping for those who need it most, such as asthmatics and those with compromised immune systems. The rest of us will probably have to keep fighting off colds the slower traditional way – boxes of tissues, the body’s natural defences and lots of hot drinks.</p><img src="https://counter.theconversation.com/content/96478/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Peter Barlow has previously received project grant funding from the Chief Scientist Office of the Scottish government and Tenovus Scotland. </span></em></p>Getting rid of this scourge is nothing to be sneezed at.Peter Barlow, Associate Professor of Immunology and Infection and Director of Research of the School of Applied Sciences, Edinburgh Napier UniversityLicensed as Creative Commons – attribution, no derivatives.