tag:theconversation.com,2011:/africa/topics/polio-vaccination-30244/articlesPolio vaccination – The Conversation2022-08-21T20:03:12Ztag:theconversation.com,2011:article/1889892022-08-21T20:03:12Z2022-08-21T20:03:12ZThe latest polio cases have put the world on alert. Here’s what this means for Australia and people travelling overseas<figure><img src="https://images.theconversation.com/files/479994/original/file-20220818-459-q63sig.jpg?ixlib=rb-1.1.0&rect=1%2C1%2C997%2C664&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/covid-19-measles-ebola-vaccinated-doctor-2120184491">Shutterstock</a></span></figcaption></figure><p>Until recently, polio had only been detected in a handful of countries, thanks to global eradication efforts.</p>
<p>But this year’s polio alerts in the United States, United Kingdom and Israel are a reminder that as long as poliovirus is found anywhere, it is a potential problem everywhere. </p>
<p>That could include Australia.</p>
<p>Here’s what the latest polio cases mean for Australia – including under-vaccinated communities and people travelling internationally.</p>
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<h2>The US case</h2>
<p>In July this year, a young man in Rockland County, New York, developed paralysis and was diagnosed with polio, the <a href="https://www.statnews.com/2022/07/21/n-y-state-detects-polio-case-first-in-the-u-s-since-2013/">first US case since 2013</a>.</p>
<p>He had never been vaccinated against polio, which is not uncommon among <a href="https://forward.com/news/512089/polio-rockland-county-new-york-vaccine-orthodox-jew/">Orthodox Jewish people</a> <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8549591/">in some countries</a>. Rockland County has the highest percentage of Orthodox Jewish people in the US. Currently, only <a href="https://health.ny.gov/diseases/communicable/polio/county_vaccination_rates.htm">about 60%</a> of children in the county are vaccinated against polio, compared with <a href="https://www.cdc.gov/nchs/fastats/immunize.htm">more than 90%</a> nationally.</p>
<p>As of August 12, poliovirus was <a href="https://www1.nyc.gov/site/doh/about/press/pr2022/nysdoh-and-nycdohm-wastewater-monitoring-finds-polio-urge-to-get-vaccinated.page">still being detected</a> in sewage in New York City and other counties in New York State, indicating the virus is still circulating in the community.</p>
<p>The reason there have been no further cases of paralysis reflects the fact that only around <a href="https://www.who.int/news-room/fact-sheets/detail/poliomyelitis">one in 200 people</a> infected by the virus develops paralysis. </p>
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Read more:
<a href="https://theconversation.com/polio-in-new-york-an-infectious-disease-doctor-explains-this-exceedingly-rare-occurrence-187518">Polio in New York – an infectious disease doctor explains this exceedingly rare occurrence</a>
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<h2>A child in Israel</h2>
<p>One <a href="https://twitter.com/propublica/status/1558140096028737539">indirect link</a> to the New York man may be in Jerusalem where, in March 2022, poliovirus <a href="https://www.who.int/emergencies/disease-outbreak-news/item/2022-DON366">was found</a> in sewage and <a href="https://www.nature.com/articles/s41564-022-01201-0">one case</a> of paralysis occurred in an unvaccinated child.</p>
<p>Vaccination rates among Ultra-Orthodox Jewish people in Israel have been historically low, including <a href="https://apnews.com/article/coronavirus-pandemic-health-middle-east-religion-israel-557e9d18f3f78f4fc141eeddaaefb8eb">low uptake</a> of COVID vaccines.</p>
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<h2>UK ramps up vaccination</h2>
<p>In June this year, the UK government <a href="https://www.gov.uk/government/news/poliovirus-detected-in-sewage-from-north-and-east-london">reported</a> wastewater surveillance in north and east London between February and May had identified poliovirus on consecutive occasions. </p>
<p>This indicated a provisional “silent” outbreak and prompted health officials to instigate catch-up vaccination campaigns. No cases of paralysis have been reported.</p>
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<p>This is reminiscent of an earlier “silent” outbreak of polio in 2013-2014 when, after decades without a case, Israel <a href="https://www.pnas.org/doi/10.1073/pnas.1808798115">detected</a> poliovirus in wastewater samples in many areas, mainly in southern regions.</p>
<p>Stool surveys indicated the outbreak was restricted mainly to children under the age of ten in the Bedouin population of <a href="https://pubmed.ncbi.nlm.nih.gov/27334457/">southern Israel</a>. The virus originated in Pakistan and arrived in Israel via Cairo and then, probably, through Bedouin communities in Egypt and Israel.</p>
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Read more:
<a href="https://theconversation.com/polio-vaccine-boosters-offered-to-london-children-an-expert-explains-whats-going-on-188564">Polio vaccine boosters offered to London children – an expert explains what's going on</a>
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<h2>Hang on, hasn’t polio been eradicated?</h2>
<p>It’s tempting to think polio has been eradicated. </p>
<p>The last case of locally acquired polio in Australia <a href="https://www1.health.gov.au/internet/main/publishing.nsf/Content/cda-pubs-cdi-2002-cdi2602-cdi2602l.htm">was in 1972</a>. Australia was declared polio-free on October 29, 2000, along with the other 36 countries in the Western Pacific Region of the World Health Organization. The last case reported in Australia <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2660702/">was in 2007</a>, when a student contracted the infection in Pakistan.</p>
<p>The <a href="https://polioeradication.org">Global Polio Eradication Initiative</a>, launched in 1988, successfully eliminated wild poliovirus from all but two countries – Pakistan and Afghanistan – where in recent years there have been very few cases. </p>
<p>In <a href="https://polioeradication.org/where-we-work/afghanistan/">Afghanistan</a>, there were four cases last year and one so far this year. In <a href="https://polioeradication.org/where-we-work/pakistan/">Pakistan</a>, there was one case in 2021 and 14 so far this year.</p>
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Read more:
<a href="https://theconversation.com/polio-were-developing-a-safer-vaccine-that-uses-no-genetic-material-from-the-virus-185721">Polio: we're developing a safer vaccine that uses no genetic material from the virus</a>
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<p>The recent cases and wastewater detected polioviruses in the UK, US and Israel are not the wild variety. Instead, they are derived from the oral polio vaccine.</p>
<p>When a child receives a dose of the oral vaccine, they excrete the virus in the stool for several weeks. In very rare cases, the vaccine-derived virus mutates to a form that causes paralysis. This form is called a circulating vaccine-derived poliovirus (cVDPV). This occurs only in populations where polio vaccine coverage is low.</p>
<p>Just recently, cVDPV was reported in the Democratic Republic of the Congo, Mozambique and Yemen, as well as in wastewater in five other countries.</p>
<p>Australia, like all high-income countries, does not use the oral polio vaccine. Instead, children receive <a href="https://immunisationhandbook.health.gov.au/contents/vaccine-preventable-diseases/poliomyelitis">injectable inactivated polio vaccine</a>, which prevents paralysis but does not prevent transmission of the virus. </p>
<p>This is why so-called silent outbreaks can occur in countries that use the injectable vaccine. This is when the virus spreads from child to child but does not cause paralysis.</p>
<h2>What are the implications for Australia?</h2>
<p>Given Australia’s open international borders, there is no reason why someone who has recently received the oral polio vaccine wouldn’t enter the country and excrete the virus.</p>
<p>In Australia, at the age of five, <a href="https://www.health.gov.au/node/38782/childhood-immunisation-coverage/current-coverage-data-tables-for-all-children#five-year-olds">about 95% of children</a> are fully vaccinated against polio. </p>
<p>However, there are places with lower vaccine coverage, such as <a href="https://www.theguardian.com/australia-news/2021/aug/14/when-covid-came-to-the-anti-vax-capital-of-australia">Byron Shire</a> in northern New South Wales, with lower rates of childhood vaccination, including against polio.</p>
<p>This vaccine-hesitant community is vulnerable to the introduction of polio and has had cases of diphtheria, whooping cough, measles and tetanus in recent years.</p>
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<p>Unlike some other Orthodox Jewish communities overseas, there is no evidence this community in Australia is more vaccine hesitant than other Australians.</p>
<h2>How do we look out for cases?</h2>
<p>For years, wastewater monitoring has been routinely implemented in many countries. This acts as an early warning system to identify and rapidly mitigate the spread of many pathogens, <a href="https://theconversation.com/sewage-surveillance-is-the-next-frontier-in-the-fight-against-polio-105012">including poliovirus</a>, hepatitis viruses and, recently, SARS-CoV-2 (the virus that causes COVID).</p>
<p>At wastewater treatment facilities, sewage from an entire region is combined. This allows scientists to <a href="https://www.nature.com/articles/s41564-022-01201-0">detect pathogens</a> at the population level and before anyone presents with symptoms.</p>
<p>In December 2017, Victoria’s environmental testing program <a href="https://www.health.vic.gov.au/media-releases/health-surveillance-system-detects-poliovirus">detected</a> a rare type of poliovirus in pre-treated sewage from the Western Treatment Plant in Melbourne. </p>
<p>No cases of paralytic polio were detected but all Victorians up to the age of 19 were offered three doses of vaccine, free of charge, as part of catch-up arrangements.</p>
<p>Australia’s poliovirus infection outbreak response plan <a href="https://www.health.gov.au/sites/default/files/documents/2022/05/poliovirus-infection-outbreak-response-plan-for-australia.pdf">focuses on</a> clinical surveillance (where health workers report suspected cases to health authorities) and laboratory investigations of people who present with acute paralysis. </p>
<p>While the plan refers to examples of wastewater surveillance overseas, it does not propose a specific strategy in Australia. </p>
<p>Other than Victoria, it is not clear where wastewater polio surveillance is being conducted in Australia.</p>
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Read more:
<a href="https://theconversation.com/sewage-surveillance-is-the-next-frontier-in-the-fight-against-polio-105012">Sewage surveillance is the next frontier in the fight against polio</a>
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<h2>What happens next?</h2>
<p>Australia is just as vulnerable to importations of poliovirus – both wild and vaccine-derived – as any other country.</p>
<p>Australia should ensure routine wastewater surveillance for poliovirus is conducted, at least in metropolitan areas.</p>
<p>Community-based vaccination campaigns should be sensitively conducted in vaccine-hesitant communities, such as in Byron Shire, to achieve high coverage.</p>
<p>Education should also be provided through GPs to parents planning to travel to Jerusalem, New York City and Rockland County. They should ensure all travelling family members are fully vaccinated against polio. Visitors to Israel may be able to access a dose of oral polio vaccine in that country for their children (which will prevent them being infected) but this is not available in the US.</p>
<p>Poliovirus enters the body through the mouth, usually from hands contaminated with the stool of an infected person. So parents should also pay special attention to their children’s hand hygiene, particularly if travelling overseas to any of the locations mentioned.</p><img src="https://counter.theconversation.com/content/188989/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Michael Toole receives funding from the National Health and Medical Research council.</span></em></p>Polio cases in the US, UK and Israel remind us that this could also happen in Australia. Here’s what we should watch out for.Michael Toole, Associate Principal Research Fellow, Burnet InstituteLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1875182022-07-22T21:53:50Z2022-07-22T21:53:50ZPolio in New York – an infectious disease doctor explains this exceedingly rare occurrence<figure><img src="https://images.theconversation.com/files/475697/original/file-20220722-18-x3p6wo.jpg?ixlib=rb-1.1.0&rect=2%2C0%2C1794%2C1196&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Polio is endemic only in Afghanistan and Pakistan in 2022.</span> <span class="attribution"><a class="source" href="https://newsroom.ap.org/detail/Polio/221757d74c22419095b557a6d3e4ab75/photo?Query=polio&mediaType=photo&sortBy=arrivaldatetime:desc&dateRange=Anytime&totalCount=1705&currentItemNo=2">Sarah Poser, Meredith Boyter Newlove/CDC via AP</a></span></figcaption></figure><p><em>The first case of polio in the U.S. <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5779436/">since 2013</a> was announced by New York state <a href="https://health.ny.gov/press/releases/2022/2022-07-21_polio_rockland_county.htm">health officials on July 21, 2022</a>. The U.S. resident had not been vaccinated.</em></p>
<p><em>Polio was a common cause of paralysis in children before <a href="https://theconversation.com/lessons-from-how-the-polio-vaccine-went-from-the-lab-to-the-public-that-americans-can-learn-from-today-145604">safe and effective vaccines were invented</a> in the mid-20th century. Thanks to global vaccination campaigns, polio is now almost eradicated, with <a href="https://polioeradication.org/polio-today/polio-now/this-week/">only 13 cases of endemic wild poliovirus reported</a> in 2022 to date worldwide.</em></p>
<p><em>The New York patient reportedly contracted a form of polio that can be traced back to the live, but weakened, poliovirus used in the <a href="https://www.cdc.gov/vaccines/vpd/polio/public/index.html">oral polio vaccine</a>. This version of the vaccine has <a href="https://www.cdc.gov/media/pressrel/r990617.htm">not been used in the U.S. since 2000</a>. Health officials said the virus affecting the male patient, who has muscle weakness and paralysis, <a href="https://health.ny.gov/press/releases/2022/2022-07-21_polio_rockland_county.htm">likely originated somewhere overseas</a>, where oral vaccines are still administered.</em></p>
<p><em><a href="https://scholar.google.com/citations?user=6yMIM1MAAAAJ&hl=en&oi=ao">William Petri</a> is an infectious disease specialist and chair of the World Health Organization’s <a href="https://polioeradication.org/tools-and-library/current-research-areas/polio-research-committee/">Polio Research Committee</a>. Here he explains what <a href="https://www.cdc.gov/vaccines/vpd/polio/hcp/vaccine-derived-poliovirus-faq.html">vaccine-derived poliovirus</a> is and why the inactivated polio vaccine administered in the U.S. today can’t cause it.</em></p>
<h2>What are the two kinds of polio vaccine?</h2>
<p>Vaccines introduce a harmless version of a pathogen to your body. The idea is that <a href="https://www.cdc.gov/vaccines/hcp/conversations/understanding-vacc-work.html">they train your immune system</a> to fight off the real germ if you ever encounter it.</p>
<p>The oral polio vaccine, <a href="https://doi.org/10.1126/science.288.5471.1593">originally developed by Albert Sabin</a>, uses a live but weakened poliovirus that one swallows in a sugar cube or droplet. Scientists weaken – or attenuate – the virus so it can no longer cause disease. </p>
<p>The other kind of polio vaccine was <a href="https://doi.org/10.1126/science.288.5471.1593">originally developed by Jonas Salk</a>. It contains inactivated, dead virus. It is administered by an injection.</p>
<p>In the U.S., children receive the inactivated polio vaccine <a href="https://www.cdc.gov/vaccines/schedules/hcp/imz/child-adolescent.html">at 2, 4 and 6 months of age</a>. It provides nearly complete protection from paralytic polio.</p>
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<span class="caption">A boy in Pakistan receives a dose of the oral polio vaccine.</span>
<span class="attribution"><a class="source" href="https://newsroom.ap.org/detail/PakistanPolio/23a6599533e34577b64f4932393fa80a/photo?Query=polio&mediaType=photo&sortBy=arrivaldatetime:desc&dateRange=Anytime&totalCount=1705&currentItemNo=17">AP Photo/Muhammad Sajjad</a></span>
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<h2>How can the live vaccine lead to a case of polio?</h2>
<p>The weakened form of the live virus in the oral vaccine cannot cause disease. However, because the vaccine is given orally, the weakened virus is excreted in the feces and can <a href="https://www.who.int/news-room/questions-and-answers/item/poliomyelitis-vaccine-derived-polio">spread from someone who is vaccinated to their close contacts</a>. If the weakened virus circulates person to person for long enough, it can mutate and regain its ability to cause paralysis.</p>
<p>The <a href="https://www.who.int/news-room/questions-and-answers/item/poliomyelitis-vaccine-derived-polio">mutated virus can then infect people</a> in communities with poor sanitation and low vaccination rates, causing disease and even paralysis. </p>
<p>This is an exceedingly rare occurrence. With more than 10 billion doses of the oral polio vaccine administered since 2000, there have been <a href="https://polioeradication.org/polio-today/polio-now/this-week/circulating-vaccine-derived-poliovirus/">fewer than 800 cases of vaccine-derived polio</a> reported.</p>
<p>Apparently, the current patient in New York was somehow exposed to a mutated poliovirus that had been transmitted after vaccination overseas. Earlier this summer, routine surveillance spotted <a href="https://www.who.int/news/item/22-06-2022-vaccine-derived-poliovirus-type-2-(vdpv2)-detected-in-environmental-samples-in-london--uk">vaccine-derived poliovirus in London’s sewage system</a>, but no cases have been reported there. </p>
<h2>Why use the oral vaccine anywhere if it comes with this risk?</h2>
<p>There’s a positive aspect to the fact that the weakened live virus can circulate in the community once oral vaccine recipients shed it in their feces. Traveling a feces-to-oral route, it can <a href="https://polioeradication.org/polio-today/polio-prevention/the-vaccines/opv/">help induce immunity</a> even in people who weren’t directly vaccinated. The oral polio vaccine is also <a href="https://doi.org/10.1093/infdis/jiu128">cheaper and easier to administer</a> than inactivated polio vaccines.</p>
<p>Most importantly, the live-virus vaccine stops transmission of wild poliovirus in a way that the inactivated-virus vaccine does not. The <a href="https://doi.org/10.1126/science.abb8588">eradication of polio</a> in the Americas, Europe and Africa has been accomplished solely through the use of the live oral vaccine. Once polio has been wiped from a continent, then it is safe to stop using the oral live vaccine and use only the inactivated vaccine, <a href="https://www.cdc.gov/cpr/polioviruscontainment/diseaseandvirus.htm">which does prevent disease in recipients</a> and does not pose the rare risk of vaccine-derived paralytic polio.</p>
<p><a href="https://polioeradication.org/nopv2/">A new and safer oral polio vaccine</a> that has been engineered not to mutate is now <a href="https://doi.org/10.1126/science.abb8588">replacing the earlier live-virus vaccine</a>. Thus, even this extremely rare complication of polio vaccination should soon become a thing of the past.</p>
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<figcaption><span class="caption">WHO: Polio Eradication – Reaching Every Last Child.</span></figcaption>
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<h2>How close is the world to eradicating polio?</h2>
<p>Thanks to <a href="https://polioeradication.org">tremendous global effort</a>, two of the three viruses that cause polio have been eradicated. The world is now on the verge of eradicating the final one, wild poliovirus 1 (WPV1).</p>
<p><a href="https://polioeradication.org/polio-today/polio-now/this-week/">Today endemic polio is found</a> only in Pakistan, with 12 cases of paralytic polio so far in 2022, and Afghanistan, with just one case this year. Africa has two cases, imported from overseas, which are being contained by additional vaccination campaigns.</p>
<p>Once wild poliovirus has been eradicated from the planet, vaccination efforts may be able to switch to the inactivated polio vaccine, eliminating the risk of any future vaccine-derived cases.</p><img src="https://counter.theconversation.com/content/187518/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>William Petri receives research funding from the NIH and the Gates Foundation.</span></em></p>The oral polio vaccine – which is no longer given in the US – relies on a live but weakened virus that can actually be passed from person to person.William Petri, Professor of Medicine, University of VirginiaLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1528062021-01-14T13:21:16Z2021-01-14T13:21:16ZThe great polio vaccine mess and the lessons it holds about federal coordination for today’s COVID-19 vaccination effort<figure><img src="https://images.theconversation.com/files/378566/original/file-20210113-23-12pkx5x.jpg?ixlib=rb-1.1.0&rect=0%2C299%2C4991%2C3539&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Elementary students initially received polio vaccines at school.</span> <span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/view-of-a-classroom-as-children-receive-polio-vaccinations-news-photo/618896932">PhotoQuest/Archive Photos via Getty Images</a></span></figcaption></figure><p>I nervously fell into a long line of fellow first graders in the gymnasium of St. Louis’ Hamilton Elementary School in the spring of 1955. We were waiting for our first injection of the new polio vaccine.</p>
<p>The National Foundation for Infantile Paralysis – with money raised through its annual March of Dimes campaign – had sponsored field tests for a vaccine developed by Jonas Salk. The nonprofit had acquired sufficient doses to inoculate all the nation’s first and second graders through simultaneous rollouts administered at their elementary schools. The goal was to give 30 million shots <a href="https://www.marchofdimes.org/mission/a-history-of-the-march-of-dimes.aspx">over three months</a>.</p>
<p>Now, more than six decades later, attention focuses on the rollout of two COVID-19 vaccines, following their <a href="https://www.fda.gov/emergency-preparedness-and-response/coronavirus-disease-2019-covid-19/pfizer-biontech-covid-19-vaccine">emergency use authorization</a> by the U.S. Food and Drug Administration. States have begun to administer them in a <a href="https://www.npr.org/2021/01/03/952969795/what-the-u-s-can-do-about-vaccine-rollout-issues">rocky and frustratingly slow delivery process</a> – while <a href="https://www.statista.com/statistics/1102816/coronavirus-covid19-cases-number-us-americans-by-day/">hundreds of thousands of new cases</a> continue to be diagnosed daily in the U.S.</p>
<p>While not necessarily comforting, it is useful to recognize that the early days and weeks of mass distribution of a new medication, particularly one that is intended to address a fearful epidemic, are bound to be frustrating. Only after examining the complex polio vaccine distribution process as documented in papers collected in the <a href="https://www.eisenhowerlibrary.gov/">Dwight D. Eisenhower Presidential Library</a> did I come to understand how partial my childhood memories actually were.</p>
<h2>Vaccine distribution, 65 years ago</h2>
<p>After I received my polio shot, I remember my parents’ relief.</p>
<p>The polio virus causes flu-like symptoms in most people who catch it. But in a minority of those infected, the brain and spinal cord are affected; polio can cause paralysis and even death. With the distribution of Salk’s vaccine, the <a href="https://global.oup.com/academic/product/polio-9780195152944">much-feared stalker of children and young adults</a> had seemingly been tamed. Within days, however, the initial mass inoculation program <a href="https://www.jstor.org/stable/4638326">went off the rails</a>.</p>
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<a href="https://images.theconversation.com/files/378571/original/file-20210113-23-6mt7t0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Jonas Salk poses with a flask in lab" src="https://images.theconversation.com/files/378571/original/file-20210113-23-6mt7t0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/378571/original/file-20210113-23-6mt7t0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=789&fit=crop&dpr=1 600w, https://images.theconversation.com/files/378571/original/file-20210113-23-6mt7t0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=789&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/378571/original/file-20210113-23-6mt7t0.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=789&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/378571/original/file-20210113-23-6mt7t0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=992&fit=crop&dpr=1 754w, https://images.theconversation.com/files/378571/original/file-20210113-23-6mt7t0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=992&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/378571/original/file-20210113-23-6mt7t0.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=992&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">The world initially rejoiced as Salk’s vaccine came online. He declined to patent it, to make it available to all.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/view-of-american-scientist-and-physician-jonas-salk-news-photo/109274461">PhotoQues/Archive Photos via Getty Images</a></span>
</figcaption>
</figure>
<p>Immediately following the government’s licensing of the Salk vaccine, the National Foundation for Infantile Paralysis contracted with private drug companies for US$9 million worth of vaccine (around $87 million today) – about 90% of the stock. They planned to provide it free to the <a href="https://www.google.com/books/edition/Patenting_the_Sun/qIHhAAAAMAAJ?hl=en">country’s first and second graders</a>. But just two weeks after the first doses were administered, the Public Health Service reported that six inoculated children had come down with polio.</p>
<p>As the number of such incidents grew, it became clear that some of the shots were causing the disease they were meant to prevent. A <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1383764/">single lab</a> had inadvertently released adulterated doses.</p>
<p>After considerable fumbling and outright denial, Surgeon General Leonard Steele first pulled all tainted vaccine off the market. Then, less than a month after the initial inoculations, the U.S. <a href="https://oac.cdlib.org/findaid/ark:/13030/kt3c6031cw/entire_text/">shut down distribution entirely</a>. It wasn’t until the introduction of a <a href="https://www.statnews.com/2018/03/01/albert-sabin-polio-vaccine/">new polio vaccine</a> in 1960, created by Albert Sabin, that public trust returned.</p>
<h2>History’s lessons for 2021</h2>
<p>This story offers several lessons relevant to the COVID-19 vaccine distribution just now getting rolling.</p>
<p>First, federal coordination of an emergent lifesaving medical product is critical.</p>
<p>The federal government had declined to play an active oversight and coordination role for the polio vaccine, but still wanted the credit. The federal Department of Health, Education and Welfare (now Health and Human Services) offered no plan for distribution beyond the privately funded school-based program.</p>
<p>The department waited a full month after the vaccine was first administered before bringing together a permanent scientific clearance panel. That delay had less to do with formal procedures than with the ideological opposition of Health, Education and Welfare Secretary <a href="https://www.womenshistory.org/education-resources/biographies/oveta-hobby">Oveta Culp Hobby</a>.</p>
<p>Hobby was a political appointee who had taken office <a href="https://www.tshaonline.org/handbook/entries/hobby-oveta-culp">just months before the vaccine was approved</a>. Her reluctance to involve the federal government in matters that she believed were best left in private hands – and her oft-stated fear of “<a href="https://www.nytimes.com/1955/06/15/archives/mrs-hobby-terms-free-vaccine-idea-a-socialistic-step-charges.html">socialized medicine</a>” – meant that safety checks would be left to the private labs producing the vaccine. The results immediately caused dire problems and even avoidable deaths.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/378573/original/file-20210113-23-steevs.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="People protesting pandemic restrictions and rules, one holds a 'No vaccines' sign" src="https://images.theconversation.com/files/378573/original/file-20210113-23-steevs.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/378573/original/file-20210113-23-steevs.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/378573/original/file-20210113-23-steevs.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/378573/original/file-20210113-23-steevs.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/378573/original/file-20210113-23-steevs.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/378573/original/file-20210113-23-steevs.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/378573/original/file-20210113-23-steevs.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">In May 2020, Trump supporters in California protested against a COVID-19 vaccine months before one was even available.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/protester-holds-an-anti-vaccination-sign-as-supporters-of-news-photo/1213388386">David McNew/Getty Images News via Getty Images</a></span>
</figcaption>
</figure>
<p>Second, the polio vaccine distribution process demonstrated how vital it is for the federal government to act in ways deserving of public trust.</p>
<p>In those hopeful first few weeks of the polio vaccine distribution, those of us lining up for shots had little to fear beyond the sting of an injection. That changed quickly.</p>
<p>Once some children had in fact been harmed by the shot, obfuscation by government officials, clumsy explanations and delayed responses engulfed the entire production and distribution process in confusion and suspicion. Trust in the government and the vaccine eroded accordingly. Gallup polls found that by June 1955, almost half of the parents who responded said they <a href="http://www.ibiblio.org/pha/Gallup/Gallup.pdf">would not take any further vaccine shots</a> – and the full regimen of polio inoculation required three doses. In 1958, some drug companies halted production, citing “<a href="https://www.jstor.org/stable/4638326">public apathy</a>.” It wasn’t surprising to see a startling <a href="http://www.ibiblio.org/pha/Gallup/Gallup.pdf">upsurge in polio in 1959</a>, doubling cases from the previous year. </p>
<p>Today, with COVID-19 already highly politicized – polls suggest that a <a href="https://www.kff.org/coronavirus-covid-19/report/kff-covid-19-vaccine-monitor-december-2020/">minority of Americans will decline to take any vaccine</a> – it is critical to administer an effective vaccine delivery program in a manner that builds trust rather than undermines it.</p>
<p>Scattered reports of allergic reactions to the COVID-19 vaccine have generated not the denials of the Eisenhower administration but rather honest and realistic responses from the <a href="https://www.cdc.gov/coronavirus/2019-ncov/vaccines/safety/allergic-reaction.html">Centers for Disease Control and Prevention</a>. Particularly for vaccines that require multiple inoculations – both Pfizer and Moderna vaccines require <a href="https://www.statnews.com/2020/12/19/a-side-by-side-comparison-of-the-pfizer-biontech-and-moderna-vaccines/">two shots administered with a 21- or 28-day gap</a> – mass inoculations will require not just an initial willingness to get the first dose but the maintenance of trust sufficient to get people back for the followup. </p>
<p>There are significant differences in the social-political contexts of the era in which the polio vaccine was distributed and today, including the nature and threat of the two diseases and the technologies of the vaccines. But time and again, the COVID-19 pandemic has revealed disconcerting parallels with mistakes made in the past. The good news is vaccination works – no case of polio has originated <a href="https://www.cdc.gov/polio/what-is-polio/polio-us.html">in the U.S. since 1979</a>. </p>
<p>[<em>Research into coronavirus and other news from science</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-research">Subscribe to The Conversation’s new science newsletter</a>.]</p><img src="https://counter.theconversation.com/content/152806/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Bert Spector 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>Massive vaccine distribution efforts take a lot of coordination. The rollout of the Salk polio vaccine in the US in 1955 holds lessons for those delivering COVID-19 shots today.Bert Spector, Associate Professor of International Business and Strategy at the D'Amore-McKim School of Business, Northeastern UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1417632020-07-16T12:16:00Z2020-07-16T12:16:00ZEnding the pandemic will take global access to COVID-19 treatment and vaccines – which means putting ethics before profits<figure><img src="https://images.theconversation.com/files/347794/original/file-20200715-35-13bamf4.jpg?ixlib=rb-1.1.0&rect=8%2C0%2C5692%2C3752&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Indian health workers doing health checks in Mumbai, June 17, 2020.</span> <span class="attribution"><a class="source" href="http://www.apimages.com/metadata/Index/Virus-Outbreak/c7559479e6e14738b8817229a88fbdb3/89/0">AP Photo/Rafiq Maqbool, File</a></span></figcaption></figure><p>As COVID-19 surges in the United States and worldwide, even the richest and best insured Americans understand, possibly for the first time, what it’s like not to have the medicines <a href="https://www.nytimes.com/2020/04/14/opinion/sunday/covid-inequality-health-care.html">they need to survive</a> if they get sick. There is no coronavirus vaccine, and the best known treatment, remdesivir, only reduces <a href="https://www.technologyreview.com/2020/04/29/1000855/remdesivir-covid-hospital-save-lives/">hospital recovery time by 30%</a> and only for patients with certain forms of the disease.</p>
<p>Poorer people have always had trouble accessing essential medicines, however – even when good drugs exist to prevent and treat their conditions.</p>
<p>In the U.S., where <a href="https://indicators.ohchr.org/">there is no legal right to health</a>, insurance is usually necessary for medical treatment. Remedesivir costs about <a href="https://www.cnbc.com/2020/06/29/gileads-coronavirus-treatment-remdesivir-to-cost-3120-for-us-insured-patients.html">US$3,200 for a typical treatment course of six vials</a>, though critics argue its manufacturer, Gilead, could <a href="https://www.businesswire.com/news/home/20200512005240/en/AHF-Demands-Gilead-Price-Remdesivir-1.00-Dose">make a profit off much less</a>. Internationally, <a href="https://doi.org/10.1111/j.1748-720X.2009.00365.x">high drug prices</a> mean that critical medicines are often <a href="https://time.com/5564547/drug-prices-medicine/">available only to the richest patients</a>. </p>
<p>Access to medicines, in other words, is usually an ethical problem – not a scientific one. And that’s going to complicate the global coronavirus fight. Experts worry that any COVID-19 vaccine is likely to have a <a href="https://khn.org/news/analysis-how-a-covid-19-vaccine-could-cost-americans-dearly/">high price tag</a> and, as a result, be <a href="https://www.who.int/ethics/publications/ethics-covid-19-resource-allocation.pdf?ua=1">unequally distributed</a> according to countries’ <a href="https://www.nytimes.com/2020/06/29/health/coronavirus-remdesivir-gilead.html">purchasing power</a>, not need.</p>
<p>With a little imagination, this challenge can be overcome. My new book “<a href="https://global.oup.com/academic/product/global-health-impact-9780197514993">Global Health Impact: Extending Access to Essential Medicines</a>” documents how in past epidemics, from <a href="https://www.who.int/news-room/q-a-detail/does-polio-still-exist-is-it-curable">polio</a> and <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4337146/">Ebola</a> to HIV, the international community managed to get lifesaving drugs to patients – no matter where they lived or how much they earned.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/347755/original/file-20200715-27-d2xxu2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Afghan women in burqas vaccinate young boys" src="https://images.theconversation.com/files/347755/original/file-20200715-27-d2xxu2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/347755/original/file-20200715-27-d2xxu2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=401&fit=crop&dpr=1 600w, https://images.theconversation.com/files/347755/original/file-20200715-27-d2xxu2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=401&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/347755/original/file-20200715-27-d2xxu2.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=401&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/347755/original/file-20200715-27-d2xxu2.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/347755/original/file-20200715-27-d2xxu2.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/347755/original/file-20200715-27-d2xxu2.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">An Afghan health worker administers the polio vaccine to a child in Arghandab, Afghanistan, Aug. 17, 2018.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/an-afghan-health-worker-administers-the-polio-vaccine-to-a-news-photo/1018029676?adppopup=true">Javed Tanveer/AFP via Getty Images</a></span>
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</figure>
<h2>Past wins</h2>
<p>It took years for scientists to <a href="https://www.healthline.com/health/hiv-aids/history#:%7E:text=Azidothymidine%2C%20also%20known%20as%20zidovudine,percent%20decline%20in%20death%20rates">identify an effective treatment</a> for HIV. But by 1997, most people diagnosed with HIV in Europe and the U.S. were living long and productive lives thanks to antiretroviral drugs. </p>
<p>Meanwhile, the disease was still <a href="https://data.unaids.org/pub/report/2000/2000_gr_en.pdf">killing 2.2 million people each year</a> in sub-Saharan Africa because <a href="https://www.nytimes.com/2019/06/24/health/drugs-poor-countries-africa.html">pharmaceutical companies claimed</a> it was impossible to lower the <a href="https://www.npr.org/sections/health-shots/2019/05/30/727731380/old-fight-new-front-aids-activists-want-lower-drug-prices-now">US$10,000 to $15,000</a> annual cost per patient for antiretrovirals. </p>
<p>In response, human rights activists galvanized <a href="https://academic.oup.com/jhrp/article/1/1/14/2188684">a global AIDS campaign</a>, educating African patients about antiretrovirals, giving them the tools they required to demand treatment and even suing drug companies. Eventually, mass <a href="https://www.thebodypro.com/article/aids-2016-inside-the-massive-hiv-treatment-access-">protests erupted in South Africa</a> and elsewhere, shifting public opinion on access to medicines. </p>
<p>By 2000, <a href="https://www.wipo.int/wipo_magazine/en/2016/04/article_0001.html">competition from generic drug manufacturers</a> brought the price of antiretrovirals down to around $350 per patient per year, allowing <a href="https://doi.org/10.1093/jhuman/hun006">millions more worldwide</a> to <a href="https://jiasociety.biomedcentral.com/articles/10.1186/1758-2652-14-15">take them</a>.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/347744/original/file-20200715-27-1apgnfx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="Protesters wearing yellow 'HIV Positive' shirts hold signs and banners" src="https://images.theconversation.com/files/347744/original/file-20200715-27-1apgnfx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/347744/original/file-20200715-27-1apgnfx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/347744/original/file-20200715-27-1apgnfx.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/347744/original/file-20200715-27-1apgnfx.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/347744/original/file-20200715-27-1apgnfx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/347744/original/file-20200715-27-1apgnfx.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/347744/original/file-20200715-27-1apgnfx.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">Demonstrators in Durban, South Africa, demand lower priced HIV drugs outside the 2000 international AIDS conference.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/demonstrators-hold-banners-09-july-2000-in-the-streets-of-news-photo/51396710?adppopup=true">Yoav Lemmer/AFP via Getty Images</a></span>
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</figure>
<p>Around the same time, a <a href="https://doi.org/10.1164/rccm.200402-140OE">similar story was playing out with tuberculosis</a>, which had greatly diminished in the U.S. and Europe but remained deadly in many other places. The <a href="https://www.who.int/tb/areas-of-work/drug-resistant-tb/global-situation/en/">rise of drug-resistant strains</a> – especially in the former Soviet Union and parts of Africa and Asia – posed a particularly <a href="https://doi.org/10.1016/S1473-3099(18)30625-X">terrible challenge</a>.</p>
<p>Conventional wisdom held that people with drug-resistant TB <a href="http://www.npr.org/2008/12/21/98460202/health-is-a-human-right">couldn’t be saved</a>. The drugs were too expensive, treatment courses too long and disease management too complicated. </p>
<p>The organization <a href="https://www.devex.com/news/deal-slashes-preventive-tb-medicine-price-by-nearly-70-95942">Partners in Health</a> disproved that excuse by successfully treating 50 tuberculosis patients in Peru, then one of the world’s poorest countries. That project helped convince the World Health Organization to endorse multi-drug-resistant TB treatment. Global <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5070676/">funding for TB treatment</a> increased greatly and generic medicines were produced. Today more than <a href="http://globalhealth.pythonanywhere.com/index/disease/2015/tb#relocation_disease2015">70% of people diagnosed with drug-resistant TB receive treatment</a></p>
<h2>Ending COVID-19 ethically</h2>
<p>These health campaigns both demonstrate the virtue I call creative resolve, which is a fundamental commitment to overcoming apparent tragedy. </p>
<p>Other examples include the adoption of “<a href="https://www.historyofvaccines.org/content/articles/disease-eradication">ring vaccinations</a>” in the 1960s – a <a href="https://www.washingtonpost.com/news/worldviews/wp/2015/02/14/how-a-method-used-to-wipe-out-smallpox-is-making-a-comeback-in-the-fight-against-ebola/">contact tracing-based immunization strategy</a> pioneered in the 1960s after mass vaccinations failed to stop smallpox – and a 2010 campaign to give children in Afghanistan their <a href="https://www.globalcitizen.org/en/content/polio-afghanistan-eradication-circus/">polio vaccinations at the circus</a>.</p>
<p>Ending the global coronavirus pandemic will require similar creative resolve. </p>
<p>[<em>The Conversation’s science, health and technology editors pick their favorite stories.</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-favorite">Weekly on Wednesdays</a>.]</p>
<p>Recently, the U.S. agreed to pay $1.2 billion for <a href="https://www.usatoday.com/story/news/2020/05/21/coronavirus-covid-19-vaccine-astrozeneca-1-billion-us-300-million-doses/5237320002/">early access</a> to a promising COVID-19 vaccine in the United Kingdom and secured first access to another by the <a href="https://www.bloomberg.com/news/articles/2020-05-13/u-s-to-get-sanofi-covid-vaccine-first-if-it-succeeds-ceo-says">French pharmaceutical company Sanofi</a>, enraging citizens of those countries. Such arrangements also harm manufacturing countries like <a href="https://www.nature.com/articles/d41586-020-01756-0">Brazil</a>, Egypt and India, whose people have little access to the medicines their factories pump out.</p>
<p>Unequal access to COVID-19 medicines isn’t just a moral problem. In a global pandemic, an outbreak anywhere threatens people everywhere.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/347751/original/file-20200715-29-iejrrx.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C5534%2C3678&q=45&auto=format&w=1000&fit=clip"><img alt="Masked health workers at a pharmaceutical manufacturing company" src="https://images.theconversation.com/files/347751/original/file-20200715-29-iejrrx.jpg?ixlib=rb-1.1.0&rect=0%2C0%2C5534%2C3678&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/347751/original/file-20200715-29-iejrrx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/347751/original/file-20200715-29-iejrrx.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/347751/original/file-20200715-29-iejrrx.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/347751/original/file-20200715-29-iejrrx.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/347751/original/file-20200715-29-iejrrx.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/347751/original/file-20200715-29-iejrrx.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">Egyptian patients will get little to none of the remdesivir produced by the Egyptian drug company Eva Pharma because the US has bought up the world’s supply.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/june-2020-egypt-giza-employees-of-egyptian-pharmaceutical-news-photo/1223461292?adppopup=true">Fadel Dawood/picture alliance via Getty Images</a></span>
</figcaption>
</figure>
<p>There is some creative resolve on display in the <a href="https://medicinespatentpool.org/the-medicines-patent-pool-stands-ready-to-offer-support-as-needed-in-access-to-treatment-for-the-coronavirus/">COVID-19 fight</a>, though. </p>
<p>For example, the <a href="https://www.who.int/emergencies/diseases/novel-coronavirus-2019/global-research-on-novel-coronavirus-2019-ncov/covid-19-technology-access-pool">Medicines Patent Pool</a> – a United Nations-backed organization that encourages companies to share their patents in order to <a href="https://medicinespatentpool.org/who-we-are/about-us/">speed up innovation</a> – is pushing this method for advancing the research and development of COVID-19 drugs. </p>
<p>Other health experts are proposing new <a href="https://healthimpactfund.org/pdf/High-level-panel-draft-016-02-22-formatted.docx.pdf">medicine distribution mechanisms</a> that would send drugs and <a href="https://www.sciencemag.org/news/2020/04/tame-testing-chaos-nih-and-firms-join-forces-streamline-coronavirus-vaccine-and-drug">vaccines</a> where they’re most needed based on the net health benefits a population would receive.</p>
<p>That plan and others require smart data use. The <a href="http://globalhealth.pythonanywhere.com/">Global Health Impact Project</a>, a research collaboration that I direct, measures the effectiveness and availability of lifesaving medicines. The idea is that if we know <a href="https://doi.org/10.1371/journal.pone.0141374">which drugs are actually addressing pressing health needs and where</a>, policymakers and health organizations can craft more targeted treatment access plans. </p>
<p>Such information could be also used creatively to reward drug companies for their global health impact. Governments could create an <a href="https://www.keionline.org/book/prizes-lots-of-them">international prize</a>, say, that <a href="https://www.mercatus.org/features/mercatus-launches-prize-fund-combat-covid-19">awards funds</a> to companies based on the lives saved by their COVID-19 drugs and other essential medicines. That could offset profit as the primary motivation for drug research, development and sales.</p>
<p>And if pharmaceutical companies don’t voluntarily <a href="https://www.wto.org/english/tratop_e/trips_e/public_health_faq_e.htm">help people in poor countries</a>, those governments can do <a href="https://journals.sagepub.com/doi/10.1111/j.1748-720X.2009.00369.x">what they’ve done in past health crises</a>: let other companies produce generic versions of patented medicines, to protect the common good.</p>
<p><em>Editor’s note: This story has been corrected to reflect the disease that Afghan children were vaccinated against in 2010.</em></p><img src="https://counter.theconversation.com/content/141763/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Many universities have contributed to the Global Health Impact Organization. Its supporters are listed at: <a href="http://globalhealth.pythonanywhere.com/index/thankyou">http://globalhealth.pythonanywhere.com/index/thankyou</a></span></em></p>The high cost of pharmaceuticals often means only the richest patients get lifesaving medicines. As coronavirus drugs emerge, it will require hard, creative work to ensure they’re available to all.Nicole Hassoun, Professor of Philosophy, Binghamton University, State University of New YorkLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1339762020-03-25T12:27:30Z2020-03-25T12:27:30ZThe deadly polio epidemic and why it matters for coronavirus<figure><img src="https://images.theconversation.com/files/321088/original/file-20200317-60901-1gzviny.jpg?ixlib=rb-1.1.0&rect=4%2C0%2C3000%2C2335&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">An emergency polio ward in Boston in 1955 equipped with iron lungs. These pressurized respirators acted as breathing muscles for polio victims, often children, who were paralyzed.</span> <span class="attribution"><a class="source" href="http://www.apimages.com/metadata/Index/Associated-Press-Domestic-News-Massachusetts-Un-/ade0290b02e5da11af9f0014c2589dfb/15/0">www.apimages.com</a></span></figcaption></figure><p>The fear and uncertainty surrounding the coronavirus pandemic may feel new to many of us. But it is strangely familiar to those who lived through the polio epidemic of the last century. </p>
<p>Like a horror movie, throughout the first half of the 20th century, the polio virus arrived <a href="https://www.cdc.gov/polio/what-is-polio/polio-us.html">each summer, striking without warning</a>. No one knew how polio was transmitted or what caused it. There were wild theories that the virus spread from <a href="https://books.google.com/books?id=JumHQwdeAd0C&pg=PA10&lpg=PA10&dq=Paul+offit+cats+bananas+caused+polio&source=bl&ots=xe3GuWPgiK&sig=ACfU3U0IMY6kBzq4ObB4dFGfYXonwvS5SA&hl=en&sa=X&ved=2ahUKEwjaj5T7xrHoAhVfgnIEHRtjD2MQ6AEwAnoECAoQAQ#v=onepage&q=Paul%20offit%20cats%20bananas%20caused%20polio&f=false">imported bananas or stray cats</a>. There was no known cure or vaccine. </p>
<p>For the next four decades, <a href="https://books.google.com/books?id=p4YRDAAAQBAJ&pg=PA72&lpg=PA72&dq=polio+oshinsky+swimming+pools+closed+each+summer+playgrounds&source=bl&ots=XQDhmCcXjf&sig=ACfU3U1JWg5hO33KcCWBwUzeXtpT_O01Mg&hl=en&sa=X&ved=2ahUKEwjUkdT43bHoAhUfl3IEHRq7AI0Q6AEwCXoECAwQAQ#v=onepage&q=polio%20oshinsky%20swimming%20pools%20closed%20each%20summer%20playgrounds&f=false">swimming pools and movie theaters closed during polio season</a>
for fear of this invisible enemy. Parents stopped sending their children to playgrounds or birthday parties for fear they would “catch polio.” </p>
<p>In the outbreak of 1916, health workers in New York City would physically remove children from their homes or playgrounds if they suspected they might be infected. Kids, who seemed to be targeted by the disease, were taken from their families and isolated in sanitariums. </p>
<p>In 1952, the number of polio cases in the U.S. <a href="https://ourworldindata.org/polio">peaked at 57,879</a>, resulting in 3,145 deaths. Those who survived this highly infectious disease could end up with some form of paralysis, forcing them to use crutches, wheelchairs or to be put into <a href="https://amhistory.si.edu/polio/howpolio/ironlung.htm">an iron lung</a>, a large tank respirator that would pull air in and out of the lungs, allowing them to breathe. </p>
<p>Ultimately, poliomyelitis was conquered in 1955 by a vaccine developed by Jonas Salk and his team at the University of Pittsburgh.</p>
<p>In conjunction with the 50th anniversary celebration of the polio vaccine, I produced a documentary, “<a href="https://www.steeltown.org/poliofilm/">The Shot Felt ‘Round the World,</a>” that told the stories of the many people who worked alongside Salk in the lab and participated in vaccine trials. As a filmmaker and <a href="https://www.filmandmedia.pitt.edu/people/carl-kurlander">senior lecturer</a> at the University of Pittsburgh, I believe these stories provide hope in the fight to combat another unseen enemy, coronavirus. </p>
<h2>Pulling together as a nation</h2>
<p>Before a vaccine was available, polio caused more than <a href="https://www.cdc.gov/polio/what-is-polio/polio-us.html">15,000 cases of paralysis a year</a> in the U.S. It was the <a href="http://www.nbcnews.com/id/56324818/ns/technology_and_science-science/t/polio-vaccine-how-us-most-feared-disease-was-eradicated/#.XnkqpNNKiL8">most feared disease of the 20th century</a>. With the success of the polio vaccine, Jonas Salk, 39, became one of the most celebrated scientists in the world. </p>
<p>He refused a patent for his work, saying the vaccine belonged to the people and that to patent it would be like “patenting the Sun.” Leading drug manufacturers made the vaccine available, and <a href="https://doi.org/10.1377/hlthaff.24.3.622">more than 400 million doses</a> were distributed between 1955 and 1962, reducing the cases of polio by 90%. By the end of the century, the polio scare had become a faint memory.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/322390/original/file-20200323-112700-1lp52jt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/322390/original/file-20200323-112700-1lp52jt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/322390/original/file-20200323-112700-1lp52jt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=449&fit=crop&dpr=1 600w, https://images.theconversation.com/files/322390/original/file-20200323-112700-1lp52jt.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=449&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/322390/original/file-20200323-112700-1lp52jt.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=449&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/322390/original/file-20200323-112700-1lp52jt.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=565&fit=crop&dpr=1 754w, https://images.theconversation.com/files/322390/original/file-20200323-112700-1lp52jt.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=565&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/322390/original/file-20200323-112700-1lp52jt.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=565&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">First and second graders in San Diego line up to be vaccinated in 1955.</span>
<span class="attribution"><a class="source" href="https://www.gettyimages.com/detail/news-photo/san-diego-california-first-and-second-graders-at-the-kit-news-photo/514704620?adppopup=true">Bettman Collection via Getty Images</a></span>
</figcaption>
</figure>
<p>Developing the vaccine was a collective effort, from national leadership by President Franklin Roosevelt to those who worked alongside Salk in the lab and the volunteers who rolled up their sleeves to be experimentally inoculated. </p>
<p><a href="https://www.youtube.com/watch?v=Jp9V2p40kKw">Sidney Busis</a>, a young physician at the time, performed tracheotomies on two-year-old children, making an incision in their necks and enclosing them in iron lung to artificially sustain their breathing. His wife Sylvia was terrified that he would transmit polio to their two young sons when he came home at night. </p>
<p>In the Salk lab, a graduate student, Ethyl “Mickey” Bailey, pipetted by mouth – pulling liquid up thin glass tubes – live polio virus as part of the research process. </p>
<p>My own neighbor, Martha Hunter, was in grade school when her parents volunteered her for “the shot,” the experimental Salk vaccine that no one knew if it would work. </p>
<p><a href="https://www.history.com/this-day-in-history/franklin-roosevelt-founds-march-of-dimes">President Roosevelt,</a> who kept his own paralysis from polio hidden from the public, organized the nonprofit National Institute of Infant Paralysis, later known as the March of Dimes. He encouraged every American to send dimes to the White House to support treating polio victims and researching a cure. In the process, he changed American philanthropy, which had been largely the domain of the wealthy.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/321992/original/file-20200320-22598-1ctts2g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/321992/original/file-20200320-22598-1ctts2g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/321992/original/file-20200320-22598-1ctts2g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=491&fit=crop&dpr=1 600w, https://images.theconversation.com/files/321992/original/file-20200320-22598-1ctts2g.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=491&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/321992/original/file-20200320-22598-1ctts2g.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=491&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/321992/original/file-20200320-22598-1ctts2g.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=617&fit=crop&dpr=1 754w, https://images.theconversation.com/files/321992/original/file-20200320-22598-1ctts2g.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=617&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/321992/original/file-20200320-22598-1ctts2g.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=617&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Thousands of March of Dimes contributions were delivered to the White House in 1938.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/marguerite-missy-lehand-fdrs-secretary-opening-249571306">Everett Historical/Shutterstock.com</a></span>
</figcaption>
</figure>
<p>That was a time, said Salk’s oldest son, Dr. Peter Salk, in an interview for our film, when the public trusted the medical community and believed in each other. I believe that’s an idea we need to resurrect today. </p>
<h2>What it took to end polio</h2>
<p>Jonas Salk was 33 when he began his medical research in a basement lab at the University of Pittsburgh. He had wanted to work on influenza but switched to polio, an area where research funding was more available. Three floors above his lab was a polio ward filled to capacity with adults and children in iron lungs and rocking beds to help them breathe. </p>
<p>There were many false leads and dead ends in pursuing remedies. Even President Roosevelt traveled to Warm Springs, Georgia, believing that the water there might have curative effects. While most in the scientific community believed that a <a href="https://doi.org/10.5501/wjv.v1.i4.108">live polio virus vaccine</a> was the answer, Salk went against medical orthodoxy. </p>
<p>He pursued a <a href="https://www.sciencehistory.org/historical-profile/jonas-salk-and-albert-bruce-sabin">killed virus vaccine</a>, trying it first on cells in the lab, then monkeys and, next, young people who already had polio. There were no guarantees this would work. Ten years earlier, a <a href="https://www.passporthealthusa.com/2019/06/how-was-the-polio-vaccine-developed/">different polio vaccine</a> had inadvertently given kids polio, killing nine of them.</p>
<p>In 1953, Salk was given permission to test the vaccine on healthy children and began with his three sons, followed by a vaccination pilot study of 7,500 children in local Pittsburgh schools. While the results were positive, the vaccine still needed to be tested more widely to gain approval. </p>
<p>In 1954, the March of Dimes organized a national field trial of 1.8 million schoolchildren, the <a href="https://doi.org/10.1136/bmj.317.7167.1233">largest medical study in history</a>. The data was processed and on April 12, 1955, six years from when Salk began his research, the Salk polio vaccine was declared “safe and effective.” Church bells rang and newspapers across the world claimed “Victory Over Polio.” </p>
<h2>Vaccinations and global health security</h2>
<p>In adapting our documentary for broadcast on the <a href="https://www.huffpost.com/entry/a-shot-to-save-the-world_b_4151327">Smithsonian Channel</a>, we interviewed Bill Gates, who explained why the Bill and Melinda Gates Foundation had made eradicating polio worldwide a <a href="https://www.npr.org/2011/01/31/133377748/bill-gates-goal-get-rid-of-polio-forever">top priority</a>.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/Jp9V2p40kKw?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">The polio vaccine was developed through the painstaking work of Jonas Salk and public efforts to fund research.</span></figcaption>
</figure>
<p>Vaccines, he said, have <a href="https://www.youtube.com/watch?v=JZvpF6gaGH4">saved millions of lives</a>. He joined the World Health Organization, UNICEF, Rotary International and others to help finish the job started by the Salk vaccine, eradicating polio in the world. This accomplishment will free up resources that will no longer have to be spent on the disease. </p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/321988/original/file-20200320-22606-fyfgji.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/321988/original/file-20200320-22606-fyfgji.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/321988/original/file-20200320-22606-fyfgji.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/321988/original/file-20200320-22606-fyfgji.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/321988/original/file-20200320-22606-fyfgji.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/321988/original/file-20200320-22606-fyfgji.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/321988/original/file-20200320-22606-fyfgji.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/321988/original/file-20200320-22606-fyfgji.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 health care worker delivers an oral dose of the polio vaccine.</span>
<span class="attribution"><a class="source" href="http://www.apimages.com/metadata/Index/Pakistan-Polio/61871c83bfc4446cba55f55c0ebfeffc/166/0">AP Photo/K.M. Chaudary</a></span>
</figcaption>
</figure>
<p>Up until now, <a href="https://ourworldindata.org/smallpox-is-the-only-human-disease-to-be-eradicated-heres-how-the-world-achieved-it">smallpox</a> is the only infectious disease we have ever eliminated. But <a href="http://polioeradication.org/news-post/five-ways-the-fight-against-polio-is-a-fight-against-other-diseases/">the global infrastructure</a> that the polio eradication effort has put in place is helping to fight other infectious diseases also, such as Ebola, malaria and now coronavirus. On Feb. 5, 2020, the Bill & Melinda Gates Foundation announced it would <a href="https://www.gatesfoundation.org/Media-Center/Press-Releases/2020/02/Bill-and-Melinda-Gates-Foundation-Dedicates-Additional-Funding-to-the-Novel-Coronavirus-Response">provide US$100 million</a> to improve detection, isolation and treatment efforts and accelerate the development of a vaccine for the coronavirus. </p>
<p>These are frightening times as the coronavirus spreads in ways reminiscent of poliomyelitis. It’s instructive to remember what it took to nearly eradicate polio and a reminder of what we can do when faced with a common enemy. On Oct. 24, 2019, <a href="https://www.vox.com/2019/10/24/20930553/polio-outbreak-2019-eradication-who">World Polio Day</a>, WHO announced there were only 94 cases of wild polio in the world. The success of the polio vaccine launched a <a href="https://doi.org/10.1073/pnas.1704507114">series of vaccines</a> that negated many of the effects of infectious disease for the second half of the 20th century.</p>
<p>At the end of our film, Salk’s youngest son, Dr. Jonathan Salk, recounted how his father wondered every day why we couldn’t apply the spirit of what happened with the development of the polio vaccine to other problems, such as disease or poverty. In fighting coronavirus, perhaps the citizens and governments of the world will rise to the occasion and demonstrate what is possible when we work together. </p>
<p>[<em>Get facts about coronavirus and the latest research.</em> <a href="https://theconversation.com/us/newsletters?utm_source=TCUS&utm_medium=inline-link&utm_campaign=newsletter-text&utm_content=upper-coronavirus-facts">Sign up for our newsletter.</a>]</p><img src="https://counter.theconversation.com/content/133976/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Carl Kurlander has previously received funding for the film from the R.K. Mellon Foundation, the Pittsburgh Foundation, the Elsie H. Hillman Foundation, The Burke Foundation, and the Jewish Healthcare Foundation for the making of the polio film as well as from the University of Pittsburgh. He is not current receiving any grant funding.
</span></em></p>Polio was nearly eradicated with the Salk vaccine in 1955. At the time, little was known about this mysterious disease that paralyzed and sometimes killed young children.Carl Kurlander, Senior Lecturer, University of PittsburghLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1215982019-09-13T11:37:14Z2019-09-13T11:37:14ZA newly designed vaccine may help stamp out remaining polio cases worldwide<figure><img src="https://images.theconversation.com/files/292096/original/file-20190911-190007-1t409cv.jpg?ixlib=rb-1.1.0&rect=272%2C13%2C1870%2C1387&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The oral polio vaccine is most commonly used in the developing world, despite one big problem.</span> <span class="attribution"><a class="source" href="https://phil.cdc.gov/Details.aspx?pid=18249">CDC/Alan Janssen, MSPH</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span></figcaption></figure><p>Public health organizations around the world have been fighting for global eradication of polio since 1988. Through massive vaccination efforts, the <a href="http://polioeradication.org/polio-today/history-of-polio/">incidence of polio has gone down 99%</a> since then, with the virus eradicated from most of the countries on Earth.</p>
<p>But there have been many setbacks.</p>
<p>One particularly serious threat has surfaced over the last 15 years. Among poorly vaccinated populations, an increasing number of polio cases are due to strains of the virus that originate from one version of the vaccine itself. The Sabin vaccine, which is taken orally, is <a href="https://www.who.int/biologicals/areas/vaccines/poliomyelitis/en/">composed of live but weakened viruses</a> that won’t sicken recipients but will still create lasting immunity against polio.</p>
<p>However, through genetic changes, the weakened vaccine virus can reacquire the ability to cause paralytic polio. How this happens and how to prevent it are under active research. A new vaccine deliberately constructed to prevent the poliovirus from regaining virulence may be the answer.</p>
<h2>Virus in vaccines, attenuated or killed</h2>
<p>The <a href="https://www.who.int/en/news-room/fact-sheets/detail/poliomyelitis">virus that causes polio</a> infects the cells of the throat and intestine. People usually catch it by ingesting food or water contaminated with fecal matter from an infected person.</p>
<p>Most people infected with the polio virus have no symptoms at all; about a quarter of infections result in flu-like symptoms. However, in about 1 out of every 200 cases, the virus <a href="https://doi.org/10.1016/j.virol.2005.09.015">invades the cells of the central nervous system</a>, causing paralysis.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/292094/original/file-20190911-190050-1xdqj0r.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/292094/original/file-20190911-190050-1xdqj0r.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/292094/original/file-20190911-190050-1xdqj0r.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=594&fit=crop&dpr=1 600w, https://images.theconversation.com/files/292094/original/file-20190911-190050-1xdqj0r.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=594&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/292094/original/file-20190911-190050-1xdqj0r.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=594&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/292094/original/file-20190911-190050-1xdqj0r.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=746&fit=crop&dpr=1 754w, https://images.theconversation.com/files/292094/original/file-20190911-190050-1xdqj0r.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=746&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/292094/original/file-20190911-190050-1xdqj0r.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=746&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Illustration of a poliovirus particle.</span>
<span class="attribution"><a class="source" href="https://phil.cdc.gov/Details.aspx?pid=22498">CDC/ Sarah Poser</a>, <a class="license" href="http://creativecommons.org/licenses/by/4.0/">CC BY</a></span>
</figcaption>
</figure>
<p>Poliovirus is a very simple virus. It is composed of a shell, or capsule, made of protein. Inside the capsule is a single strand of ribonucleic acid, or RNA, that encodes the genetic information to make new virus particles. There are three poliovirus strains – PV1, PV2 and PV3. Immunity to one strain does not confer immunity to the other two, so both the original Salk and Sabin vaccines included all three.</p>
<p>The Salk vaccine, which is injected, is composed of killed viruses; the Sabin vaccine, taken orally, contains live but weakened viruses. Such weakened vaccine viruses are known as “attenuated.” The oral vaccine is both more effective and easier to administer than the injected vaccine, and so it has been the primary weapon for worldwide eradication of polio.</p>
<p>Once a child is immunized with the oral polio vaccine, the weakened virus lives in their intestine for several weeks, allowing the child to develop immunity by building up antibodies. During this time, recipients shed live viruses in their feces. The weakened viruses in the vaccine itself do not cause polio, and this shedding can help to <a href="http://polioeradication.org/polio-today/polio-prevention/the-vaccines/opv/">immunize unvaccinated people</a> that come into close contact with recently vaccinated individuals. </p>
<p>But shortly after the oral vaccine became widely used in the early 1960s, researchers discovered that some shed viruses had <a href="http://www.virology.ws/2015/09/10/why-do-we-still-use-sabin-poliovirus-vaccine/">reacquired the ability to cause paralysis</a>.</p>
<p>As the viruses multiply in the intestine, they undergo genetic changes, some of which can reverse or circumvent the original genetic changes that had made them less virulent. These vaccine-derived virulent viruses very rarely cause their vaccinated host to get polio, but, when they circulate in the population, they put unvaccinated individuals at grave risk.</p>
<p>Because of this risk, most developed countries, including the United States, have <a href="https://www.cdc.gov/vaccines/vpd/polio/public/index.html">stopped using the oral Sabin vaccine</a>, relying instead on several injections of the Salk vaccine. However, oral polio vaccine is still the most available, and reliable, vaccine in developing countries.</p>
<h2>Fine-tuning the vaccination effort</h2>
<p>One of the polio strains – type 2 polio, or PV2 – was <a href="http://polioeradication.org/news-post/global-eradication-of-wild-poliovirus-type-2-declared/">declared eradicated</a> worldwide in 2015. The challenge then became preventing new cases of type 2 polio that could stem from virus shed by newly vaccinated people. </p>
<p>To prevent these new cases of vaccine-derived type 2 polio, the World Health Organization campaigned to replace the standard oral polio vaccine with one consisting of only PV1 and PV3. This <a href="https://www.who.int/immunization/diseases/poliomyelitis/en/">switch was completed in 2016</a>. </p>
<p>Unfortunately, the vaccine-derived type 2 poliovirus continues to circulate and cause paralytic polio. Globally, <a href="http://polioeradication.org/polio-today/polio-now/this-week/">104 polio cases due to this virus occurred in 2018</a>, which was three times the number of cases due to wild viruses not derived from the vaccine. As the number of children who have no immunity to type 2 poliovirus increases, this number may rise.</p>
<p>Health officials are campaigning to eliminate all oral vaccines and rely on injected vaccines containing killed virus. However, this plan imposes logistic and financial burdens on developing countries. Meanwhile, oral type 2 vaccines are needed to stop any outbreaks of type 2 polio. And health officials have not yet figured out how to make sure unvaccinated children don’t get polio from mutated viruses shed by vaccinated people.</p>
<h2>Ensuring virulence can’t be restored</h2>
<p>But what if researchers created a vaccine from a weakened live virus that’s unlikely revert to virulence? That’s one of the strategies that <a href="https://doi.org/10.2217/fmb-2019-0196">several research groups</a> are working on now.</p>
<p>As part of this effort, scientists have now mapped out in detail the <a href="https://doi.org/10.1016/j.cell.2017.03.013">steps that allow the PV2 vaccine strain to regain virulence</a>. </p>
<p>Just three simple genetic mutations, each of which alone has a small effect, when combined, dramatically increase the virulence of the PV2 strain in mice in the lab. And, all three are found in the viruses shed by <a href="https://doi.org/10.1016/j.cell.2017.03.013">recent vaccine recipients</a>.</p>
<p>Virulence can also be reestablished in the intestine if the genetic material of the PV2 strain recombines with that of another virus. The second virus can be the weakened PV1 or PV3 from the vaccine, <a href="https://doi.org/10.1016/j.cell.2017.03.013">or a related virus</a> such as coxsackie, a common virus in children.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/292101/original/file-20190911-190050-1or0jb1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/292101/original/file-20190911-190050-1or0jb1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/292101/original/file-20190911-190050-1or0jb1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=479&fit=crop&dpr=1 600w, https://images.theconversation.com/files/292101/original/file-20190911-190050-1or0jb1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=479&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/292101/original/file-20190911-190050-1or0jb1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=479&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/292101/original/file-20190911-190050-1or0jb1.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=601&fit=crop&dpr=1 754w, https://images.theconversation.com/files/292101/original/file-20190911-190050-1or0jb1.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=601&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/292101/original/file-20190911-190050-1or0jb1.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=601&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Rather than making the vaccine from purified virus as Albert Sabin did, today’s researchers are tweaking the virus they will use to create the vaccine.</span>
<span class="attribution"><a class="source" href="http://www.apimages.com/metadata/Index/Watchf-Associated-Press-Domestic-News-Ohio-Unit-/486be8a50c8f406a9ece810ead1dee5d/156/0">AP Photo/Gene Smith</a></span>
</figcaption>
</figure>
<h2>Designing the virus for the vaccine</h2>
<p>Having discovered exactly how the type 2 vaccine virus regains virulence, scientists figured out ways that these specific genetic changes could be prevented. Using the tools of molecular biology, <a href="http://dx.doi.org/10.2139/ssrn.3400856">they made four important changes to the PV2 genome</a> that should stop it from regaining virulence.</p>
<p>Part of the virus’s RNA genome has to fold up into a lollipop-like shape in order for proteins to be made. This structure is disrupted in the weakened vaccine strain, but a single mutation in the virulent strain allows it to reassemble. So that can’t happen, the scientists changed the genetic sequence of the RNA in a way that no single nucleotide change would let the RNA fold into the stable lollipop structure again.</p>
<p>Second, they changed the genetic sequence of the enzyme that copies the RNA to make it more accurate. That way fewer genetic mutations would occur in the vaccine recipient’s intestine. </p>
<p>Third, another change to the same enzyme reduced the chance that the virus could pick up genes by recombining with other viruses in the recipient.</p>
<p>And, fourth, they rearranged the virus’s genes so that replacing certain regions of its own RNA with genetic information from a wild virus, such as coxsackie, would be lethal for it.</p>
<p>Researchers have produced two candidate PV2 viruses that grew well in experimental cells, were not virulent in a mouse model and were genetically stable. <a href="https://doi.org/10.1016/S0140-6736(19)31279-6">A phase 1 clinical trial of vaccines made from these viruses</a> showed that they were well tolerated, produced an immune response and had reduced (but not zero) reversion to virulence compared to the original oral vaccine for PV2.</p>
<p>These and other new, <a href="https://doi.org/10.1371/journal.ppat.1003001">rationally designed viruses</a> have the potential to provide good protection from polio with a reduced risk of creating new outbreaks due to circulating vaccine-derived polio virus.</p>
<p>[ <em>Like what you’ve read? Want more?</em> <a href="https://theconversation.com/us/newsletters?utm_source=TCUS&utm_medium=inline-link&utm_campaign=newsletter-text&utm_content=likethis">Sign up for The Conversation’s daily newsletter</a>. ]</p><img src="https://counter.theconversation.com/content/121598/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Patricia L. Foster receives funding from the US Army Research Office. She is a member of the Union of Concerned Scientists and Concerned Scientists at Indiana University.</span></em></p>A challenge in eradicating polio comes from a version of the vaccine itself, which relies on live but attenuated virus. Rationally designing a new vaccine could help get rid of polio once and for all.Patricia L. Foster, Professor Emerita of Biology, Indiana UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/1050122018-10-19T10:37:35Z2018-10-19T10:37:35ZSewage surveillance is the next frontier in the fight against polio<figure><img src="https://images.theconversation.com/files/241330/original/file-20181018-67194-xbcd3i.jpg?ixlib=rb-1.1.0&rect=128%2C261%2C3311%2C2322&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Monitoring sewage for virus allows for a quick public health response if any polio is detected.</span> <span class="attribution"><a class="source" href="http://www.apimages.com/metadata/Index/Pharmawater-Factories/169f4ff3a4c24e7781780a5422328838/10/0">AP Photo/Matt Rourke</a></span></figcaption></figure><p>The world is at the brink of eradicating polio. <a href="http://polioeradication.org/where-we-work/polio-endemic-countries/">Only three countries</a> now have ongoing transmission: Nigeria, Afghanistan and Pakistan. And in 2017, there were <a href="http://polioeradication.org/news-post/working-toward-a-polio-free-future-2017-in-review/">only a couple dozen cases</a> of paralytic wild polio reported worldwide – a massive decrease from the estimated <a href="http://polioeradication.org/polio-today/history-of-polio/">350,000 cases reported across 125 countries in 1988</a>. Development of the polio vaccine and global vaccination efforts are at the heart of this monumental public health achievement.</p>
<p>Epidemiologists typically detect polio transmission based on reported cases of acute flaccid paralysis (AFP). The World Health Organization certifies a country as polio-free if there are no reports of AFP for three years. But AFP is a severe outcome that <a href="http://www.who.int/news-room/fact-sheets/detail/poliomyelitis">occurs in a very small fraction</a> of polio infections. It’s just the tip of the iceberg – one case of AFP indicates substantial underlying polio transmission in a population. </p>
<p>This is why now, as the world approaches the final stages of polio eradication, environmental surveillance becomes key. Looking for poliovirus in sewage is more sensitive than counting up cases of AFP. It can detect virus shed in the feces of non-paralyzed people infected with polio – what epidemiologists call the silent circulation of polio.</p>
<p>Environmental microbiologists have <a href="https://doi.org/10.1146/annurev.mi.49.100195.002333">studied pathogens in sewage for decades</a>, but its use as a public health surveillance tool is relatively new. As epidemiologists who specialize in modeling the spread of disease, we wondered if we could estimate the intensity of infection in a population by analyzing counts of virus in its sewage. The discovery of <a href="https://www.health.gov.il/PublicationsFiles/ICDC_317.pdf">polio transmission in Israel in 2013</a> – the <a href="http://polioeradication.org/where-we-work/polio-free-countries/">first in that country since 1988</a> – provided a way for us to test whether our model, coupled with environmental surveillance data from different parts of the world, could be used to assess how much silent transmission is still happening globally.</p>
<h2>Characterizing a polio outbreak in Israel</h2>
<p>Given all the progress made toward polio eradication, it was disturbing to realize <a href="https://doi.org/10.2807/1560-7917.ES2013.18.38.20586">polio was actively being transmitted</a> <a href="https://doi.org/10.2807/1560-7917.ES2014.19.7.20708">in Israel in 2013</a>. A sewage surveillance system – set up in 1989 by the Israeli health department to detect poliovirus – sounded the alarm. The Ministry of Health worked quickly to vaccinate the public, and fortunately none of the infections resulted in paralysis.</p>
<p>To track polio in human waste in Israel, samples are automatically collected from sewage trunk lines and treatment plants approximately weekly. Back at the country’s Central Virology Laboratory, they’re checked for poliovirus.</p>
<p>Most of the positive sewage samples during the 2013 outbreak came from the Negev region of Israel, and most of those from predominantly Bedouin communities. <a href="https://doi.org/10.1126/science.342.6159.679">Based on molecular characteristics of the virus</a> isolated from the sewage, scientists know that the virus originated in Pakistan, then traveled into the region, diverging into Egypt, Israel and Syria. For a virus, even tightly guarded geopolitical borders are fluid.</p>
<p>To understand what kept the polio transmission going, we needed to better characterize Bedouin movement patterns. Where people travel provides pathways for them to potentially spread the virus. For example, larger Jewish communities such as Beer Sheva are economic hubs; Bedouins from communities throughout the region travel there daily. In addition, many communities send children to regional schools, another potential hub of transmission.</p>
<p>Poor sanitary conditions provide an important route for the poliovirus to move from host to host – remember, infected people excrete viable virus in their feces. Epidemiologists knew surprisingly little about the water and sanitation infrastructure of these Bedouin communities, beyond that they were highly variable and often poor compared to nearby Jewish communities.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/241329/original/file-20181018-67164-ll836t.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/241329/original/file-20181018-67164-ll836t.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/241329/original/file-20181018-67164-ll836t.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/241329/original/file-20181018-67164-ll836t.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/241329/original/file-20181018-67164-ll836t.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/241329/original/file-20181018-67164-ll836t.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/241329/original/file-20181018-67164-ll836t.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/241329/original/file-20181018-67164-ll836t.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">Where people encounter sewage-contaminated water, they may also be exposed to poliovirus.</span>
<span class="attribution"><a class="source" href="http://www.apimages.com/metadata/Index/Mideast-Gaza-Sewage-Crisis/92540e8fc91a4c66874e104b9671480c/8/0">AP Photo/Khalil Hamra</a></span>
</figcaption>
</figure>
<h2>Creating a model for how polio spread</h2>
<p>The Central Virology Laboratory and Ministry of Health recognized the potential in their data, but no one had developed a theory to convert environmental surveillance into public health metrics. Because of <a href="https://scholar.google.com/citations?user=PJAQ7AQAAAAJ&hl=en&oi=ao">our</a> <a href="https://sph.umich.edu/faculty-profiles/eisenberg-joseph.html">experience</a> <a href="https://scholar.google.com/citations?user=RhyNk3EAAAAJ&hl=en&oi=sra">in</a> modeling environmentally transmitted infectious diseases, we met with Central Virology Laboratory and Ministry of Health officials on the ground during the later stages of the epidemic and began collaborating on a new approach to the problem.</p>
<p>A mathematical model allows epidemiologists to use what we know about a situation’s underlying biological mechanisms to better interpret or extract more information from data. We knew a number of things in this case: the relative levels of poliovirus in various communities’ sewage over time, the coverage of the vaccination campaigns, and the differences in transmission between the wild virus and the attenuated vaccine virus. Our goal was to come up with a model that would explain how the disease was transmitted through the population in Israel that would match the observed changes in sewage polio levels over time.</p>
<p><a href="https://doi.org/10.1073/pnas.1808798115">Using new analytical methods, we estimated</a> that in Rahat, the largest predominantly Bedouin community that sustained significant transmission, 56 percent of the at-risk population – primarily children under 10 – was infected.</p>
<p>Positive polio samples from the environment only alert public health officials that transmission is happening. Our model provides additional information about how many people were infected. Without a model, researchers would have no way of estimating the extent of the outbreak – the poliovirus in the sewage could have been collected from many people shedding a little or a few people shedding a lot. But because outbreaks follow recognizable patterns, the dynamic changes in polio concentration can actually tell us a lot about how the disease is moving through the population.</p>
<p>There is always uncertainty in model predictions, so corroboration with multiple data sources is important. In this outbreak, we were able to compare to crude estimates of infection <a href="https://doi.org/10.1016/j.jcv.2015.03.005">based on community stool samples</a>.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/241328/original/file-20181018-67188-bvk2aq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/241328/original/file-20181018-67188-bvk2aq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/241328/original/file-20181018-67188-bvk2aq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=404&fit=crop&dpr=1 600w, https://images.theconversation.com/files/241328/original/file-20181018-67188-bvk2aq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=404&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/241328/original/file-20181018-67188-bvk2aq.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=404&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/241328/original/file-20181018-67188-bvk2aq.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=508&fit=crop&dpr=1 754w, https://images.theconversation.com/files/241328/original/file-20181018-67188-bvk2aq.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=508&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/241328/original/file-20181018-67188-bvk2aq.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"></a>
<figcaption>
<span class="caption">Administering vaccine at the first signs of silent circulation can quickly stop a nascent polio outbreak.</span>
<span class="attribution"><a class="source" href="http://www.apimages.com/metadata/Index/Pakistan-Polio/8320416c5eed42848a273fb9bf454231/29/0">AP Photo/K.M. Chaudary</a></span>
</figcaption>
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<h2>Monitoring environment for silent transmission</h2>
<p>As we approach the final stages of polio eradication, environmental measures will become the only feasible way to detect polio transmission. And this silent spread of the virus must be halted to fully eradicate the disease. Waiting until there’s a paralytic case means there’s a lot of polio around and containing it with vaccination efforts becomes more difficult.</p>
<p><div data-react-class="Tweet" data-react-props="{"tweetId":"888401952656297987"}"></div></p>
<p>Environmental surveillance efforts are growing in all three polio-endemic countries. Indeed, since the success seen in Israel in identifying and quickly containing transmission by administering oral polio vaccine, many countries have <a href="http://polioeradication.org/news-post/expansion-of-environmental-surveillance-for-poliovirus-aiding-in-regional-eradication-efforts/">begun to implement polio environmental surveillance</a>. WHO is working toward developing <a href="http://polioeradication.org/wp-content/uploads/2016/07/WHO_V-B_03.03_eng.pdf">organized environmental surveillance standards</a> akin to the well-established standards for acute flaccid paralysis.</p>
<p>Beyond polio, environmental surveillance can and should be extended to other infectious diseases shed into sewage – enteroviruses, typhoid and cholera are prime candidates. Epidemiologists can then use modeling approaches to translate surveillance data to describe population patterns, allowing public health officials to respond rapidly to outbreaks.</p><img src="https://counter.theconversation.com/content/105012/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Marisa Eisenberg receives funding from the National Institutes of Health and National Science Foundation. </span></em></p><p class="fine-print"><em><span>Andrew Brouwer receives funding from the National Institutes of Health. </span></em></p><p class="fine-print"><em><span>Joseph Eisenberg receives funding from the National Institutes of Health. </span></em></p>Polio can be circulating through a community long before anyone is paralyzed. Monitoring sewage for the virus lets public health officials short-circuit this ‘silent transmission.’Marisa Eisenberg, Associate Professor of Complex Systems, Epidemiology, and Mathematics, University of MichiganAndrew Brouwer, Research Investigator in Epidemiology, University of MichiganJoseph Eisenberg, Professor and Chair of Epidemiology, University of MichiganLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/905802018-03-23T10:31:39Z2018-03-23T10:31:39ZInching closer to a world without polio<figure><img src="https://images.theconversation.com/files/211471/original/file-20180322-165571-ymubad.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">What will it take to finish polio off in the last three countries where it persists?</span> <span class="attribution"><a class="source" href="http://www.apimages.com/metadata/Index/Pakistan-Fighting-to-Vaccinate/6be7219ce1464481af4fdcf431f11bca/3/0">AP Photo/B.K. Bangash</a></span></figcaption></figure><p>At its height in the 1940s and ‘50s, <a href="https://www.cdc.gov/features/poliofacts/">polio paralyzed more than 35,000 Americans every year</a>. But thanks to vaccines as well as good hygiene and sanitation practices, polio has largely been forgotten in the developed world.</p>
<p>Now, even in less-developed regions, it’s close to being wiped out entirely. But there are still challenges to overcome before polio can join smallpox as a virus that has been eradicated worldwide. </p>
<p>With the support of the <a href="http://polioeradication.org">World Health Organization</a>, the <a href="https://www.gatesfoundation.org/What-We-Do/Global-Development/Polio">Bill & Melinda Gates Foundation</a> (a strategic partner of The Conversation US that provides funding for The Conversation internationally), <a href="https://my.rotary.org/en/take-action/end-polio">Rotary International</a> and others, public health workers and volunteers work tirelessly and in dangerous conditions to vaccinate every one of the world’s children. The number of polio cases globally dropped from 350,000 in 1988 to <a href="http://www.who.int/mediacentre/factsheets/fs114/en/">just 37 in 2016</a>. Thirty years ago, polio was regularly found in 125 of the world’s 190 or so countries. Today, only three countries continue to see regular cases: Pakistan, Nigeria and Afghanistan.</p>
<p>Of these, Pakistan is closest to becoming polio-free thanks to its persistent, innovative vaccination campaign programs. But its poor security, weak health system and lack of proper sanitation work against this effort.</p>
<p>The lessons infectious disease preparedness and response researchers <a href="https://scholar.google.com/citations?user=0M6hB44AAAAJ&hl=en&oi=ao">like</a> <a href="http://bush.tamu.edu/scowcroft/fellows/">us</a> are learning in Pakistan, during what’s hopefully a final push against polio, will also apply elsewhere, as public health experts work to wipe out other infectious diseases around the world.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/211397/original/file-20180321-165577-1hppxsa.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/211397/original/file-20180321-165577-1hppxsa.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/211397/original/file-20180321-165577-1hppxsa.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=458&fit=crop&dpr=1 600w, https://images.theconversation.com/files/211397/original/file-20180321-165577-1hppxsa.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=458&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/211397/original/file-20180321-165577-1hppxsa.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=458&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/211397/original/file-20180321-165577-1hppxsa.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=575&fit=crop&dpr=1 754w, https://images.theconversation.com/files/211397/original/file-20180321-165577-1hppxsa.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=575&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/211397/original/file-20180321-165577-1hppxsa.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=575&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Transmission electron micrograph of polioviruses.</span>
<span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/File:Polioviruses.jpg">Graham Beards</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<h2>Polio in people and in the environment</h2>
<p>Wild poliovirus is not particularly hardy and can’t survive for long in the environment. If the virus cannot find an unvaccinated person to serve as its host, it will die. This fact means vaccination efforts can fully exterminate the virus by denying it a place to live in human hosts.</p>
<p>The world’s polio eradication campaign has already done away with <a href="http://www.who.int/features/factfiles/polio/en/">two of the three naturally occurring wild polioviruses</a>. Wild poliovirus type 2 was last seen in 1999, and there has not been a case of wild poliovirus type 3 since 2012.</p>
<p>Polio spreads primarily through water contaminated with the feces of an infected person. Where sources of drinking water come into contact with sewage waste – often the case in developing countries like Pakistan – the virus spreads easily.</p>
<p>To complicate matters, nearly <a href="https://www.cdc.gov/polio/us/hcp.html">3 out of 4 people</a> infected with the poliovirus never have any symptoms at all. So most carriers of polio never know they harbor the virus, or that they’re spreading it to others.</p>
<p>In addition, those who do have symptoms usually seem to have the flu, with fever, headaches, body aches and vomiting. <a href="http://www.who.int/mediacentre/factsheets/fs114/en/">In only around 1 percent of cases</a> do symptoms include temporary or permanent paralysis.</p>
<p>This means that it is possible for the virus to exist and spread in a community even when there are no diagnosed cases of polio. For that reason, public health workers use two different measures to gauge the success of a vaccination effort: the number of people diagnosed with polio, and how much of the virus is found in the environment.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/211472/original/file-20180322-165547-tj50x0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/211472/original/file-20180322-165547-tj50x0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/211472/original/file-20180322-165547-tj50x0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=440&fit=crop&dpr=1 600w, https://images.theconversation.com/files/211472/original/file-20180322-165547-tj50x0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=440&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/211472/original/file-20180322-165547-tj50x0.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=440&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/211472/original/file-20180322-165547-tj50x0.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=553&fit=crop&dpr=1 754w, https://images.theconversation.com/files/211472/original/file-20180322-165547-tj50x0.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=553&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/211472/original/file-20180322-165547-tj50x0.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=553&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 health worker gives a polio vaccine to a child at a railway station in Pakistan.</span>
<span class="attribution"><a class="source" href="http://www.apimages.com/metadata/Index/Pakistan-Polio-Workers-Killed/225c7743762a4f499b5d9e859e459621/8/0">AP Photo/Fareed Khan</a></span>
</figcaption>
</figure>
<h2>Cultural challenges</h2>
<p>In Pakistan, these two measures paint somewhat different pictures of disease eradication. The not-so-good news is that <a href="http://www.endpolio.com.pk/images/polio-briefer/Pakistan-Polio-Update-DECEMBER-2017.pdf">16 percent of the water sources tested in 2017</a> contain the polio virus, a slight increase from 2016 levels. </p>
<p>The better news is that from 2014 to 2017, the number of new polio cases <a href="http://www.endpolio.com.pk/images/polio-briefer/Pakistan-Polio-Update-DECEMBER-2017.pdf">dropped a whopping 97 percent</a>, from 306 cases to just eight. The country’s government, with the support of the international community, has vaccinated most Pakistanis, which no doubt accounts for the impressive drop in diagnosed cases. However, because vaccination is not universal, the virus persists in some regions of Pakistan and poses a threat to those who are not vaccinated or who have not received vaccination boosters as scheduled.</p>
<p>There are several cultural barriers to wiping out polio in Pakistan. Vaccinations are usually given at health clinics and transit points, where public health workers can make contact with a large share of the population. <a href="http://polioeradication.org/where-we-work/pakistan/">Mobile vaccination units</a> reach people in other locations, but cannot safely get to children in high-conflict areas.</p>
<p>In many of these areas, <a href="https://blogs.cdc.gov/global/2017/10/24/overcoming-obstacles-to-polio-eradication-in-pakistan/">armed militants refuse</a> to let public health officials vaccinate children, claiming that the polio vaccine is part of a <a href="https://doi.org/10.1186/s12992-016-0195-3">Western plot</a> to sterilize Muslims. In 2012, the Taliban, which remain in control in some mountainous areas, <a href="https://doi.org/10.1186/s12992-016-0195-3">imposed a ban on vaccinations</a>, which slowed the polio eradication effort. Furthermore, polio vaccine campaign workers have been targets of violence, as seen most recently in the <a href="https://www.nytimes.com/2018/01/22/health/polio-pakistan-killing.html">killing of a mother-daughter vaccination team in January</a> and an <a href="https://www.independent.co.uk/news/world/asia/pakistan-polio-vaccination-team-militants-ambush-two-dead-islamic-extremism-cia-osama-bin-laden-a8261931.html">ambush this past week in a remote tribal area</a> that killed two medical workers and wounded two others.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/211473/original/file-20180322-165580-t3l6u3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/211473/original/file-20180322-165580-t3l6u3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/211473/original/file-20180322-165580-t3l6u3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/211473/original/file-20180322-165580-t3l6u3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/211473/original/file-20180322-165580-t3l6u3.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/211473/original/file-20180322-165580-t3l6u3.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/211473/original/file-20180322-165580-t3l6u3.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/211473/original/file-20180322-165580-t3l6u3.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">With armed security, a Pakistani health worker marks a house after administering polio vaccine.</span>
<span class="attribution"><a class="source" href="http://www.apimages.com/metadata/Index/Pakistan-Polio/12b58f7c0a8c472a81b772618b592a36/1/0">AP Photo/Shakil Adil</a></span>
</figcaption>
</figure>
<p>In order to overcome some of the challenges, members of the eradication campaign <a href="https://doi.org/10.1186/s12992-016-0195-3">have coordinated vaccination efforts</a> with military operations. When a large military offense in 2015 pushed the Taliban out of the northern provinces of Pakistan, it <a href="https://www.rotary.org/en/new-polio-strategy-working-pakistan">cleared the way</a> for hundreds of thousands of children to receive vaccination. </p>
<p>High illiteracy rates, extreme poverty and religious beliefs also can cause <a href="https://doi.org/10.1186/s12992-016-0195-3">parents to refuse vaccines</a> – in Pakistan and elsewhere – for their children. In these instances, education and outreach are vitally important. Helping parents <a href="https://doi.org/10.1073/pnas.1504019112">understand the dangers of disease</a> may help overcome misinformation about the vaccine and increase positive association with vaccination, as it has in the United States. </p>
<h2>Pharmaceutical challenges</h2>
<p>Public health officials have <a href="https://www.cdc.gov/vaccines/vpd/polio/index.html">two types of polio vaccine</a> in their medical supply kit: an oral vaccine and an inactivated vaccine. Both are necessary to eradicate polio. The <a href="http://www.who.int/biologicals/areas/vaccines/polio/ipv/en/">oral vaccine</a> is made from live weakened virus. The inactivated version is made with dead virus.</p>
<p>The oral vaccination <a href="http://www.virology.ws/2015/09/10/why-do-we-still-use-sabin-poliovirus-vaccine/">works significantly better</a> against naturally occurring poliovirus, known as wild poliovirus. Additionally, the administration method – being given by mouth – is thought to increase vaccine uptake because it does not require an injection.</p>
<p>The body builds immunity from this live vaccine, and then can withstand the virus if exposed to it in the future. Countries where polio is present must use the oral vaccine in order to eliminate wild poliovirus because the inactivated vaccine does not <a href="https://www.pakistankakhudahafiz.com/understanding-polio-eradication-campaign-pakistan/">stop its transmission</a> since it <a href="http://www.virology.ws/2015/09/10/why-do-we-still-use-sabin-poliovirus-vaccine/">produces lower levels of mucosal immunity</a>. </p>
<p>Though necessary, using the live oral vaccine comes with some challenges. For example, it can cause <a href="http://www.who.int/features/qa/64/en/">vaccine-derived</a> cases of polio, which include <a href="https://www.sciencedirect.com/science/article/pii/B9781437716047004231">cases of paralysis</a>. In this unfortunate and extremely rare scenario, the vaccine meant to prevent a terrible illness directly transmits it. Of the 10 billion doses of oral polio vaccine administered since 2000, there have only been <a href="http://www.who.int/features/qa/64/en/">760 cases</a> of vaccine-derived polio. </p>
<p>Though the oral vaccine is vital to the eradication of wild poliovirus, its use must be discontinued as soon as the wild virus is wiped out. Otherwise, it runs the risk of hindering complete eradication by <a href="http://www.virology.ws/2015/09/10/why-do-we-still-use-sabin-poliovirus-vaccine/">perpetuating existence of poliovirus in the environment</a> through human excrement and continuing to introduce new vaccine-derived cases of the disease. </p>
<p>Once Pakistan is declared free of wild poliovirus, the eradication campaign must switch to using the inactivated vaccine.</p>
<p>Because the inactivated vaccine provokes a weaker immune response, it doesn’t effectively disrupt transmission of wild poliovirus. But it does <a href="https://doi.org/10.15585/mmwr.mm6649a4">protect against</a> the weaker vaccine-derived poliovirus, and it doesn’t contribute to vaccine-derived cases. Once the only remaining strains are vaccine-derived, inactivated vaccines can be used to completely wipe out the disease.</p>
<p>It is likely that a world without polio may not be too far off in the future — and then infectious disease researchers can make use of the lessons learned in Pakistan as they move the fight to other diseases elsewhere around the world.</p><img src="https://counter.theconversation.com/content/90580/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 organization that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.</span></em></p>Pakistan had only eight new diagnoses of polio in 2017. The virus’ days look numbered – but health workers have their work cut out for them to eradicate the devastating disease once and for all.Christine Crudo Blackburn, Deputy Director, Pandemic & Biosecurity Policy Program, Scowcroft Institute of International Affairs, Bush School of Government and Public Service, Texas A&M UniversityMorten Wendelbo, Research Fellow, American University School of Public AffairsLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/904432018-01-25T13:34:32Z2018-01-25T13:34:32ZNigerian vaccination campaigns may be threatened by new round of rumours<figure><img src="https://images.theconversation.com/files/203029/original/file-20180123-182965-r1mnxo.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">The polio vaccination campaign in Nigeria is being hampered.</span> <span class="attribution"><span class="source">Flickr/Center for Disease Control </span></span></figcaption></figure><p>When a rumour surfaced in 2003 that Nigeria’s polio vaccine was possibly being contaminated with <a href="http://www.thisdaylive.com/index.php/2017/10/18/dsphcda-rumour-of-killer-vaccine-stalling-routine-immunisation-in-nigeria/">anti-fertility agents</a> a boycott of the vaccine ensued and the country’s polio immunisation campaign was <a href="http://journals.plos.org/plosmedicine/article?id=10.1371/journal.pmed.0040073">dealt a heavy blow</a>. </p>
<p>The boycott lasted for nearly 15 months – from February 2003 to July 2004 – and it had devastating consequences. The polio caseload shot up. And by 2008, Nigeria alone accounted for 86% of all the polio cases on the continent. Since the boycott the country has struggled to be declared polio free. </p>
<p>The country’s polio immunisation campaign, and its entire routine immunisation programme, face another possible setback. A round of rumours has been circulating that people dressed in Army uniforms were forcefully vaccinating primary and secondary school children and injecting them with unknown diseases. Social media was flooded with rumours that the campaign is a ploy to infect the children of the region with the <a href="http://dailypost.ng/2017/10/12/monkeypox-massob-accuses-nigerian-government-importing-deadly-vaccines-iran/">Monkey Pox Virus</a> aimed to wipe out the people of the region. The rumours caused massive panic and even led to the closure of schools in the south east and <a href="https://www.bbc.com/pidgin/tori-41697794">north east of Nigeria</a> as parents have rushed to take their children home. </p>
<p>The military exercise was started in September last year and the rumours came at a time when the Nigerian Army was conducting Special Security and Training Exercise, code-named Crocodile Smile 2’ for the South-South and South West zones of Nigeria. </p>
<p>The Nigerian government dismissed the social media reports, declaring that only the federal, state and local government health agencies are authorised to <a href="https://guardian.ng/news/fg-dismisses-military-involvement-in-monkeypox-vaccination/">administer vaccines</a> to pupils nationwide. </p>
<p>But the country’s <a href="http://www.afro.who.int/news/stakeholders-flag-critical-campaign-final-onslaught-against-polio">efforts to eradicate polio</a> could be hanging in the balance. The <a href="http://www.thisdaylive.com/index.php/2017/10/18/dsphcda-rumour-of-killer-vaccine-stalling-routine-immunisation-in-nigeria/">reports</a> from state health care agencies are that the rumours are starting to take their toll.</p>
<p>Nigeria is still not polio free. In 2014, it came close, after being <a href="https://theconversation.com/new-polio-outbreak-threatens-nigerias-steady-march-to-eradication-63888">removed</a> from the list of polio endemic countries in the world. But new cases have since emerged and it remains the only country in Africa and one of three in the world (the others being Afghanistan and Pakistan) that has not eradicated polio. </p>
<p>Worringly the boycott may have led to a transmission of the virus to other countries. Cases of the virus genetically linked to those originating in Nigeria have been found in <a href="https://www.canada.ca/en/news/archive/2005/05/spread-polio-yemen-indonesia.html">Yemen</a> and <a href="https://www.the-scientist.com/?articles.view/articleNo/23346/title/Nigeria-polio-strain-in-Indonesia/">Indonesia</a> which had already eliminated the disease.</p>
<p>Nigerian health authorities are concerned that in addition to affecting the polio campaign, the rumours could affect routine immunisation in general. The worst case scenario would be that diseases that should have been eliminated could continue to be transmitted.</p>
<h2>Why the rumours stuck</h2>
<p>The rumours that caused the 2003 polio vaccine boycott in northern Nigeria were fuelled and festered by a combination of factors and circumstances. </p>
<p>Firstly, they came at a time when people had had bad experiences with government health interventions. A few years earlier 11 children in the northern state of Kano had died during a meningitis clinical trial conducted by <a href="https://www.theguardian.com/world/2011/aug/11/pfizer-nigeria-meningitis-drug-compensation">Pfizer</a>. </p>
<p>Secondly, there were political tensions linked to the 2003 presidential election which led to a distrust of the government at the time and support of the boycott. </p>
<p>Thirdly, the rumours were effectively confirmed by influential and highly placed <a href="https://www.ncbi.nlm.nih.gov/pubmed/24294986">political and religious leaders</a> who gave them credence. </p>
<p>A spokesman for one of the state governors was quoted as saying: </p>
<blockquote>
<p>our people have become really concerned about polio vaccine. </p>
</blockquote>
<p>In addition to these statements some political and religious leaders in Kano, Zamfara and Kaduna – all states in northern Nigeria – called on parents not to allow their children to be immunised. </p>
<h2>Rescuing health campaigns</h2>
<p>There are several important steps that the Nigerian government must take to neutralise rumours before they lead to dire health consequences. It must start by building <a href="https://www.ncbi.nlm.nih.gov/pubmed/20085957">public trust</a>. </p>
<figure class="align-center ">
<img alt="" src="https://images.theconversation.com/files/203026/original/file-20180123-182941-1btij85.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/203026/original/file-20180123-182941-1btij85.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=450&fit=crop&dpr=1 600w, https://images.theconversation.com/files/203026/original/file-20180123-182941-1btij85.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=450&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/203026/original/file-20180123-182941-1btij85.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=450&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/203026/original/file-20180123-182941-1btij85.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=566&fit=crop&dpr=1 754w, https://images.theconversation.com/files/203026/original/file-20180123-182941-1btij85.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=566&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/203026/original/file-20180123-182941-1btij85.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">Nigeria is the only African country still affected by polio. A worker examines a 12-year-old child in Adamawa, Nigeria.</span>
<span class="attribution"><span class="source">Flickr/Center for Disease Development</span></span>
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<p>But it is also important for the government to combat ignorance with knowledge about the vaccine. Before any immunisation exercise is conducted, citizens must be given adequate information. Health workers must be equipped to answer questions that people may have. Readily available pre-packaged frequently asked questions pamphlets would be helpful. And the media must also be brought on board from the outset. </p>
<p>To combat false rumours governments and relevant authorities must articulate and disseminate appropriate counter messages. The message must provide answers to the fears that led to the rumours in the first place. And should be disseminated through the same channels used by those spreading the rumours. </p>
<p>Government must also promptly and appropriately respond to the concerns of high profile individuals such as politicians, and of the <a href="http://www.path.org/vaccineresources/files/Combatting_Antivac_Rumors_UNICEF.pdf">populations they represent</a>.</p>
<p>And lastly, health interventions must be provided by the publicly <a href="http://www.path.org/vaccineresources/files/Combatting_Antivac_Rumors_UNICEF.pdf">recognised health agency of government</a> – rather than agencies that could be questioned.</p><img src="https://counter.theconversation.com/content/90443/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Oyewale Tomori is affiliated with the Biovaccine Nigeria Limited, a new public-private partnership company for the production of vaccines in Nigeria. I serve as Chairman of the Board of the company, inaugurated on 19th January 2018. </span></em></p>Social media rumours are putting Nigeria’s vaccination campaigns at risk.Oyewale Tomori, Fellow, Nigerian Academy of ScienceLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/767292017-12-07T11:59:29Z2017-12-07T11:59:29ZVaccines aren’t enough – we’re working on a way to stop the polio virus for good<figure><img src="https://images.theconversation.com/files/197816/original/file-20171205-23037-1kx93y9.jpg?ixlib=rb-1.1.0&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>There were just 74 cases of polio <a href="http://polioeradication.org/tools-and-library/policy-reports/annual-%20reports/">reported worldwide in 2015</a>. Thanks to a global vaccination drive, this crippling disease, which once affected hundreds of thousands of people a year, is now on the verge of extinction. The World Health Organisation estimates its eradication programme has saved around 5m people from a <a href="https://www.microbiologysociety.org/uploads/assets/uploaded/9f4ef1a8-fbb5-4a6d-904fa54e94b8df9e.pdf">lifetime of paralysis</a>.</p>
<p>But what happens when polio is finally gone? To make sure it does not come back, worldwide vaccination will have to continue. To keep producing a vaccine with current technology, we will have to retain enormous live stocks of the polio virus. This will run the risk of the virus escaping into the wild and restarting the disease – the opposite of what the vaccination programme is designed to do.</p>
<p>My colleagues and I are part of an international effort to come up with a new way of producing a polio vaccine that does not rely on us keeping the virus alive. The basic principle of a vaccine is to expose the body to a molecule known as an antigen that stimulates the immune system into fighting the related disease. This way, when the body encounters the actual disease, it has learnt how to react to it. </p>
<p>Vaccines have been in use in one form or another <a href="http://amhistory.si.edu/polio/virusvaccine/history.htm">since the 10th century</a> when ancient Chinese healers exposed healthy patients to powdered scabs from smallpox sufferers. Modern vaccine development relies on more controlled and safer forms of antigen exposure. In the case of virus-carried diseases like polio, the antigen is most often a weakened or deactivated version of the virus, made from a live strain.</p>
<p>One alternative idea is to develop a virus-like particle (VLP) assembled from the proteins that make up the coat or <a href="https://www.ncbi.nlm.nih.gov/pubmed/20047040">“capsid” of the virus</a>. They contain no genetic material from the virus and so are sometimes called “empty capsids”. This makes them safe to manufacture and use without risk of spreading the actual disease. Scientists have already used this method to develop successful vaccines <a href="http://www.sciencedirect.com/science/article/pii/S0264410X12015563">against hepatitis B</a> and <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1451224/">human papillomavirus (HPV)</a></p>
<p>To create a VLP for poliovirus, we would like to use empty capsids that are made naturally during its normal growth cycle. The problem is that, without any genetic material inside them, these are <a href="http://jgv.microbiologyresearch.org/content/journal/jgv/10.1099/0022-1317-70-6-1453#tab2">structures are unstable</a> when exposed to heat.</p>
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<span class="caption">Polio vaccination has saved 5m people from paralysis.</span>
<span class="attribution"><span class="source">Shutterstock</span></span>
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<p>Our research group has tried a number of ways to create stable capsids for the VLPs. Our first step was to select strains of poliovirus that were inherently more resistant to heat. We repeatedly heated a sample of the virus to increasing temperatures and then exposed it to cultured cells. This enabled us to identify virus strains that were still infectious to the cells – and therefore stable – even when heated up to 57°C. </p>
<p>To further demonstrate these mutant strains were more stable, we used a test known as a <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3470038/">particle stability thermal release assay (PaSTRy)</a>. This involves staining the molecules that make up the virus’s capsid, and the genetic material, inside with dyes that fluoresce (give off light) when exposed to the environment. Our more stable viruses didn’t fluoresce after they had been heated, which showed they were still in tact.</p>
<p>We then isolated the mutations that made these strains so resistant to heat and used them as a model to produce <a href="http://jvi.asm.org/content/early/2016/12/01/JVI.01586-16.abstract">empty capsids</a> that had the desired stability. Other researchers in our group have <a href="http://journals.plos.org/plospathogens/articleid=10.1371/journal.ppat.1006117">also identified mutations</a> that reduce the capsids’ sensitivity to temperature changes and so could also generate more stable VLPs. Some of the mutant strains are proving to be even more stable than the inactivated polio vaccine currently in use.</p>
<h2>Making the vaccine</h2>
<p>We still need to work out the best way to use these VLPs to produce a viable vaccine. In particular, we want to develop a novel system that will produce VLPs in large numbers and with a minimum of specialised equipment. Several different systems are currently being studied including yeast, insect or plant cells. In most cases, we use a type of DNA molecule called plasmids to drive the yeast, plant or bacterial cells to produce these proteins. The VLPs <a href="https://www.ncbi.nlm.nih.gov/pubmed/28811473">are then assembled</a> from these proteins either within the cell or during the purification process.</p>
<p>At the University of Leeds, we are focused on using a yeast species, <em>Pichia pistoris</em>. Yeast has a significant advantage over other systems because it can be grown in large quantities using fermenters. This makes it relatively simple to use them to produce vaccines on a large scale, something that has <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4939942/">already been demonstrated</a> for the Chikungunya virus.</p>
<p>Once we can replicate this process for the polio vaccine and manufacture it on a large scale, we can start looking forward to the day when we are confident the disease has been banished for good.</p><img src="https://counter.theconversation.com/content/76729/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Keith Grehan works for the University of Leeds as part of a WHO-funded consortium involving experts at the Universities of Leeds, Oxford and Reading, the John Innes Centre and the Pirbright Institute. </span></em></p>Current plans to eradicate polio mean keeping the virus alive – and risk restarting the epidemic.Keith Grehan, Postdoctoral researcher, University of LeedsLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/863162017-10-26T13:39:41Z2017-10-26T13:39:41ZAndy Serkis’s Breathe is a haunting reminder of the pre-vaccine era<figure><img src="https://images.theconversation.com/files/192060/original/file-20171026-13315-1j78t7k.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">A polio patient in an iron lung, 1940.</span> <span class="attribution"><a class="source" href="https://www.shutterstock.com/image-photo/polio-patient-iron-lung-scots-mission-242824078?src=xknqoRnE9tIg0n9tDxD57g-1-0">Shutterstock/Everett Historical</a></span></figcaption></figure><p>It is humbling to think that a disease once responsible for the paralysis of many thousands of children each year is now safely contained within the realm of period drama.</p>
<p>This week sees the release of Breathe, the directorial debut of Andy Serkis. The film charts the remarkable true story of British <a href="http://www.independent.co.uk/news/people/obituary-robin-cavendish-1382697.html">disability rights activist Robin Cavendish</a> – sensitively portrayed by actor Andrew Garfield – who pioneered technologies to promote the independence of the paralysed after being struck down by polio himself in 1958.</p>
<p>Polio is a highly contagious virus that is typically transmitted by person-to-person contact, or via exposure to contaminated food or water. Most individuals exhibit no symptoms or a few days of flu-like illness. But roughly once in every 200 infections, the virus spreads from the gut to the central nervous system, where the destruction of nerve cells gives rise to paralysis. In these cases, the <a href="https://www.cdc.gov/vaccines/pubs/pinkbook/downloads/polio.pdf">prognosis varies widely</a>. Although there is no cure for polio, some individuals recover fully with supportive treatment. Others are less fortunate, suffering permanent disability or death.</p>
<p>Breathe is in turns funny, inspiring and deeply moving. But it is the devastating effects of polio that linger longest once the end credits have rolled. One moment, Cavendish is an athletic young man whose skills on the tennis court are the envy of his peers. The next, he is paralysed from the neck down, never to walk again. He later visits a ward full of people in iron lungs – <a href="https://amhistory.si.edu/polio/howpolio/ironlung.htm">coffin-like contraptions</a> that provided artificial respiration for the worst-affected polio victims. “Why do you keep your disabled people in prison?” is Cavendish’s blunt response. It is a haunting scene.</p>
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<h2>How polio paralysed the world</h2>
<p>At its height in the 1940s and 1950s, polio was a terrible blight on society. People lived in fear of the <a href="https://www.historyofvaccines.org/timeline?timeline_categories%5B%5D=52">annual summer epidemics of paralysis</a>, which predominantly affected children. The sight of hospital wards lined with iron lungs was commonplace. One <a href="http://www.sciencedirect.com/science/article/pii/S0305748812001727">particularly severe epidemic in 1947</a> caused more than 7,000 cases of paralysis and more than 600 deaths in England and Wales alone.</p>
<p>The tide eventually turned after the development of <a href="http://www.who.int/immunization/diseases/poliomyelitis/en/">two effective polio vaccines</a>: one injected and one oral. Since their introduction in the 1950s and 1960s, progress to extinguish polio has been steady but sure. The Americas were certified polio-free <a href="https://www.cdc.gov/Mmwr/preview/mmwrhtml/00032760.htm">in 1994</a>, and <a href="http://www.who.int/mediacentre/news/releases/releaseeuro02/en/">Europe followed in 2002</a>. As recently as the early 1990s, polio caused between <a href="http://www.bmj.com/content/353/bmj.i2417/rr">500 and 1,000 cases each day</a> in India, but the country has been free of polio since 2011.</p>
<p>Though polio has not been totally eradicated globally, the world is on the brink of one of the great landmarks in medical history. The disease is at present largely restricted to <a href="https://theconversation.com/explainer-ridding-the-world-of-polio-30200">Pakistan, Afghanistan, and Nigeria</a> – and 2017 is on track for a record low, with just <a href="http://polioeradication.org/polio-today/polio-now/">12 cases of paralysis</a> due to wild poliovirus so far.</p>
<p>With each year that passes, the fear that once surrounded polio subsides. It is hard to truly appreciate the sense of dread that accompanied the first cases of an epidemic – or the anxiety of a parent hoping to shelter their child from an invisible viral menace.</p>
<h2>Eradicating viruses</h2>
<p>Other diseases have followed a similar fate to polio thanks to vaccinations. Rubella – also known <a href="http://www.who.int/mediacentre/factsheets/fs367/en/">as German measles</a> – is a virus capable of causing miscarriage, stillbirth, or severe birth impairments when it infects pregnant women. Before a vaccine was available, <a href="http://vk.ovg.ox.ac.uk/rubella">200-300 infants</a> with congenital rubella syndrome were born in the UK each year. Since the introduction of the <a href="http://www.who.int/biologicals/areas/vaccines/mmr/en/">MMR vaccine</a> in 1988, rubella has become extremely rare – there have been just <a href="https://www.gov.uk/government/publications/rubella-confirmed-cases/rubella-notifications-and-confirmed-cases-by-oral-fluid-testing-in-england-2013-to-2014-by-quarter">eight confirmed</a> in the UK since 2013, for instance.</p>
<p>More examples abound. In addition to polio and rubella, routine vaccination currently protects children against diphtheria, tetanus, whooping cough, Hib disease (Haemophilus influenzae type B), rotavirus, measles and mumps. All are potentially life-threatening illnesses that have dwindled at the hand of effective vaccination.</p>
<p>But vaccines can be a victim of their own success. When the emotional threat of a disease is lost, vaccination can feel more like a <a href="http://www.bbc.com/news/world-us-canada-41504796">lifestyle choice</a> than a life-saving precaution. Such complacency is severely misplaced. Vaccine-preventable diseases are tenacious beasts, adept at reigniting if immunisation rates drop. </p>
<p>The <a href="https://www.theguardian.com/society/2008/nov/29/health-measles-epidemic">resurgence of measles in the UK</a> following the MMR vaccine scare is testament to this – in 2016 the disease caused <a href="https://www.gov.uk/government/publications/measles-confirmed-cases/confirmed-cases-of-measles-mumps-and-rubella-in-england-and-wales-2012-to-2013">more than 500 cases</a> in England and Wales. <a href="http://www.bbc.co.uk/news/health-41332766">Recent news</a> that the UK has crossed the WHO target of immunising at least 95% of children with at least one MMR dose by their fifth birthday is long overdue.</p>
<p>Any sense of safety is also a privilege of geography. While vaccine-preventable diseases may have dwindled in the UK, many continue to plague the poorest regions of the world. The WHO estimates that <a href="http://www.who.int/mediacentre/factsheets/fs367/en/">more than 100,000 infants</a> are born with congenital rubella syndrome each year. And, as recently as 2015, measles caused an estimated <a href="http://www.who.int/mediacentre/factsheets/fs286/en/">134,200 deaths</a> globally – one every four minutes.</p>
<p>Breathe offers a timely reminder that the diseases we vaccinate against have the potential to devastate lives. When we take vaccination for granted, we do so at our peril.</p><img src="https://counter.theconversation.com/content/86316/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Edward Parker receives funding from the Medical Research Council. </span></em></p>Vaccination is not to be taken for granted.Edward Parker, Research Associate in Infectious Disease Epidemiology, Imperial College LondonLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/638882016-08-15T09:00:46Z2016-08-15T09:00:46ZNew polio outbreak threatens Nigeria’s steady march to eradication<figure><img src="https://images.theconversation.com/files/134027/original/image-20160814-25472-4y22hq.JPG?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Nigerian women who formed part of the country's previous polio immunisation campaign. </span> <span class="attribution"><span class="source">Global Polio Eradication Initiative</span></span></figcaption></figure><p><em>In 2012 Nigeria accounted for <a href="http://blogs.cdc.gov/global/2015/08/24/wipe-out-polio-in-africa-for-good/">more than half</a> of all polio cases worldwide. Within three years – and after a rigorous immunisation campaign involving more than 200 000 volunteers – the country was <a href="http://www.who.int/mediacentre/news/releases/2015/nigeria-polio/en/">removed</a> from the list of polio-endemic countries. Less than a year later two new cases of polio have been reported. This is a setback for a country that aimed to achieve polio free status by 2017. Professor Oyewale Tomori explains why Nigeria finds itself in this position.</em></p>
<p><strong>Why has there been a new outbreak of polio in Nigeria?</strong></p>
<p>Nigeria was removed from the list of polio endemic countries after a long and tortuous <a href="https://theconversation.com/why-nigeria-took-so-long-to-get-non-polio-endemic-status-44932">eradication campaign</a>.</p>
<p>But after attaining <a href="http://www.who.int/mediacentre/news/releases/2015/nigeria-polio/en/">non-polio endemic status</a> in September 2015, commitment waned and complacency set in. This was particularly evident at the levels of the national assembly, governors and local government area chairpersons. This complacency meant that polio eradication activities were no longer backed by adequate and timely counterpart funding at the state and local government area levels. This was despite a public and often <a href="http://www.thisdaylive.com/index.php/2016/07/24/buhari-pledges-timely-release-of-funds-for-polio-eradication/">vocal commitment</a> to polio eradication from Nigeria’s President Muhammadu Buhari. </p>
<p>As a result gaps remained in the quality of immunisation and surveillance activities. These were especially prominent in the country’s security compromised areas. </p>
<p>The wild poliovirus (type 1) isolates were recovered from residents in Gwoza and Jere local government areas in Borno state in northern Nigeria. Genetic sequencing suggests these isolates are most closely linked to the wild poliovirus type 1 that was last detected in the state in 2011.</p>
<p><strong>How far back does this set Nigeria in its progress to eradicate polio?</strong></p>
<p>When Nigeria was removed from the list of polio-endemic countries in 2015 it meant this was the first time the country had managed to interrupt transmission of wild poliovirus. It needed to have no new cases of the wild poliovirus reported for three successive years to finally attain a polio free status by 2017. </p>
<p>Countries have to go at least 12 months without a case before they can be considered for removal from the list of polio endemic countries. Polio-free status comes after three years without a case. </p>
<p>Although Nigeria can no longer be considered a polio endemic country analysis shows that the 2016 isolate is closely linked to a 2011 isolate. This means we were unable to detect the transmission.</p>
<p>The current outbreak has set Nigeria back by at least two years – provided that no wild polio virus is detected in the future. </p>
<p><strong>What has Boko Haram’s role been?</strong></p>
<p>The new polio cases in Nigeria were reported from children in areas of the country rendered inaccessible by Boko Haram insurgency. </p>
<p>The insecurity seriously hampered effective routine and special immunisation activities.</p>
<p>Many of the children in these areas could not be reached. So, vaccination programmes couldn’t be carried out.</p>
<p>In addition, inaccessibility also made it difficult to effectively investigate reports of acute flaccid paralysis cases. Acute flaccid paralysis is weakness in the limbs in children under 15. This signals the onset of paralytic polio, with more serious symptoms such as loss of muscle reflexes, severe muscle pain and spasms and loose or floppy limbs that are often worse on one side of the body.</p>
<p>Boko Haram has contributed significantly to the current situation by creating an environment of insecurity in the affected areas. </p>
<p><strong>What does Nigeria need to do now?</strong></p>
<p>The World Health Organisation has a set of <a href="http://apps.who.int/iris/bitstream/10665/43883/1/9789241580410_eng.pdf">International Health Regulations</a> which guide countries on how to limit the spread of diseases and public health risks. The organisation’s emergency committee has deemed the international spread of poliovirus a public health emergency of international concern. </p>
<p>Nigeria complied with the temporary recommendations issued under the regulations. This involved declaring the outbreak a national public health emergency. </p>
<p>The Federal Minister of Health and stakeholders drew up an emergency plan. Three rounds of special immunisation campaigns were carried out in the affected and surrounding areas. This was a bid to ensure that the situation was contained.</p>
<p>But the current security situation will adversely affect the implementation of the plan. The Ministry of Health will need to work closely with the country’s armed forces to ensure easy access and protection of health workers.</p>
<p>I believe the situation is serious enough for the <a href="http://www.polioeradication.org/Portals/0/Document/Aboutus/Governance/IMB/12IMBMeeting/4.2_12IMB.pdf">Presidential Task Force on Polio Eradication</a> to be convened urgently. It must agree on the positive commitment and active involvement of national assembly members, state governors and local government area chairpersons. It must also maintain the essential support of traditional and religious leaders, women’s organisations and community leaders. These groups all have a role to play in making Nigeria a polio free country. </p>
<p>Nigeria must focus on attaining polio free status over the next three years and concentrate less on prematurely celebrating victory. </p>
<p>Nigeria was eagerly looking forward to 2017 as the year it would attain polio free status. The clock has now been set to 2019.</p><img src="https://counter.theconversation.com/content/63888/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Oyewale Tomori 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>A new polio outbreak in Nigeria has hampered the country’s efforts to be declared polio free by 2017.Oyewale Tomori, President, Nigerian Academy of ScienceLicensed as Creative Commons – attribution, no derivatives.