Daniel Cole/AP

New COVID variants have changed the game, and vaccines will not be enough. We need global 'maximum suppression'

Susan Michie, UCL, Chris Bullen, University of Auckland, Jeffrey V Lazarus, Barcelona Institute for Global Health (ISGlobal), John N. Lavis, McMaster University, John Thwaites, Monash University, Liam Smith, Monash University, Salim Abdool Karim, Centre for the AIDS Program of Research in South Africa (CAPRISA), Yanis Ben Amor, Columbia University

At the end of 2020, there was a strong hope that high levels of vaccination would see humanity finally gain the upper hand over SARS-CoV-2, the virus that causes COVID-19. In an ideal scenario, the virus would then be contained at very low levels without further societal disruption or significant numbers of deaths.

But since then, new “variants of concern” have emerged and spread worldwide, putting current pandemic control efforts, including vaccination, at risk of being derailed.

Put simply, the game has changed, and a successful global rollout of current vaccines by itself is no longer a guarantee of victory.

No one is truly safe from COVID-19 until everyone is safe. We are in a race against time to get global transmission rates low enough to prevent the emergence and spread of new variants. The danger is that variants will arise that can overcome the immunity conferred by vaccinations or prior infection.

What’s more, many countries lack the capacity to track emerging variants via genomic surveillance. This means the situation may be even more serious than it appears.

As members of the Lancet COVID-19 Commission Taskforce on Public Health, we call for urgent action in response to the new variants. These new variants mean we cannot rely on the vaccines alone to provide protection but must maintain strong public health measures to reduce the risk from these variants. At the same time, we need to accelerate the vaccine program in all countries in an equitable way.

Together, these strategies will deliver “maximum suppression” of the virus.

What are ‘variants of concern’?

Genetic mutations of viruses like SARS-CoV-2 emerge frequently, but some variants are labelled “variants of concern”, because they can reinfect people who have had a previous infection or vaccination, or are more transmissible or can lead to more severe disease.

There are currently at least three documented SARS-CoV-2 variants of concern:

Similar mutations are arising in different countries simultaneously, meaning not even border controls and high vaccination rates can necessarily protect countries from home-grown variants, including variants of concern, where there is substantial community transmission.

If there are high transmission levels, and hence extensive replication of SARS-CoV-2, anywhere in the world, more variants of concern will inevitably arise and the more infectious variants will dominate. With international mobility, these variants will spread.

Brazil has vaccinated millions of people, but is also the birthplace of one of the main current variants of concern. Eraldo Peres/AP

South Africa’s experience suggests that past infection with SARS-CoV-2 offers only partial protection against the B.1.351 variant, and it is about 50% more transmissible than pre-existing variants. The B.1.351 variant has already been detected in at least 48 countries as of March 2021.

The impact of the new variants on the effectiveness of vaccines is still not clear. Recent real-world evidence from the UK suggests both the Pfizer and AstraZeneca vaccines provide significant protection against severe disease and hospitalisations from the B.1.1.7 variant.

On the other hand, the B.1.351 variant seems to reduce the efficacy of the AstraZeneca vaccine against mild to moderate illness. We do not yet have clear evidence on whether it also reduces effectiveness against severe disease.

For these reasons, reducing community transmission is vital. No single action is sufficient to prevent the virus’s spread; we must maintain strong public health measures in tandem with vaccination programs in every country.

Why we need maximum suppression

Each time the virus replicates, there is an opportunity for a mutation to occur. And as we are already seeing around the world, some of the resulting variants risk eroding the effectiveness of vaccines.

That’s why we have called for a global strategy of “maximum suppression”.

Public health leaders should focus on efforts that maximally suppress viral infection rates, thus helping to prevent the emergence of mutations that can become new variants of concern.

Prompt vaccine rollouts alone will not be enough to achieve this; continued public health measures, such as face masks and physical distancing, will be vital too. Ventilation of indoor spaces is important, some of which is under people’s control, some of which will require adjustments to buildings.

Fair access to vaccines

Global equity in vaccine access is vital too. High-income countries should support multilateral mechanisms such as the COVAX facility, donate excess vaccines to low- and middle- income countries, and support increased vaccine production.

However, to prevent the emergence of viral variants of concern, it may be necessary to prioritise countries or regions with the highest disease prevalence and transmission levels, where the risk of such variants emerging is greatest.

Those with control over health-care resources, services and systems should ensure support is available for health professionals to manage increased hospitalisations over shorter periods during surges without reducing care for non-COVID-19 patients.

Health systems must be better prepared against future variants. Suppression efforts should be accompanied by:

COVID-19 variants of concern have changed the game. We need to recognise and act on this if we as a global society are to avoid future waves of infections, yet more lockdowns and restrictions, and avoidable illness and death.

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Susan Michie is Professor of Health Psychology and Director of the Centre for Behaviour Change at University College London. She receives funding from the UK's Medical Research Council and its National Institute of Health Research. She is affiliated with the UK's Scientific Advisory Group in Emergences (SAGE) and Independent SAGE. She has acted as a consultant on COVID-19 to the Behavioural Insights team at the World Health Organization.

Chris Bullen is Professor of Public Health at the School of Population Health, The University of Auckland, where he is director of the National Institute for Health Innovation. He acknowledges support for research and education from the Health Research Council of NZ, The University of Auckland, Education NZ, the Marsden Fund, the New Zealand Ministry of Health, Auckland Council, TenCent Ltd (for research projects in China), and consultancy on two US NIH grants.

Jeffrey V Lazarus is head of the health systems group at the Barcelona Institute for Global Health (ISGlobal) and acknowledges support to ISGlobal from the Spanish Ministry of Science, Innovation and Universities through the “Centro de Excelencia Severo Ochoa 2019-2023” Programme (CEX2018-000806-S), and from the Government of Catalonia through the CERCA Programme. He is active in the thinktank Wilton Park and leads two implementation science projects funded by Gilead Sciences.

John N. Lavis is a Professor at McMaster University, Director of the McMaster Health Forum, and co-lead of the COVID-19 Evidence Network to support Decision-making (COVID-END). He acknowledges funding from the Canadian Institutes of Health Research (CIHR) and has received funding from the U.K. National Institute of Health Research and U.S. philanthropists to support COVID-END, which seeks to enhance coordination and reduce duplication in the evidence response to COVID-19. He also receives funding from governments and from CIHR and other research funding agencies for the Forum's broader work on supporting evidence-informed policymaking.

John Thwaites is Chair of Monash Sustainable Development Institute and ClimateWorks Australia which receive funding for research, education and action projects from the Australian and state governments as well as from philanthropy and industry. He is former Deputy Premier of Victoria and a member of the Australian Labor Party.

Liam Smith is the Director of BehaviourWorks Australia, an applied research unit within the Monash Sustainable Development Institute at Monash University. He receives funding from numerous government, NGO and private organisations to support the research of BehaviourWorks Australia.

Salim Abdool Karim receives funding from the South African Medical Research Council (SAMRC), the South African Department of Science and Innovation (DSI) and the National Research Foundation (NRF). He previously served as the Chair of the South African Ministerial Advisory Committee on Covid-19.

Yanis Ben Amor 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.

Monash University provides funding as a founding partner of The Conversation AU.

University College London provides funding as a founding partner of The Conversation UK.

McMaster University provides funding as a founding partner of The Conversation CA.

University of Auckland provides funding as a member of The Conversation AU.

McMaster University provides funding as a member of The Conversation CA-FR.

University of Auckland provides funding as a member of The Conversation NZ.