SeroTracker, a Canadian research group, has published the largest study to date on the global spread of SARS-CoV-2 in the journal PLOS One. The study examined antibody survey data, which were published from January to December 2020, from 9.3 million people in 74 countries and found that the number of people who had a SARS-COV-2 infection, although widely variable globally, remained fairly low in the general population.
“Unfortunately, the results show that this global pandemic is not over,” says Dr. Niklas Bobrovitz, co-lead author and and Research Associate, Department of Critical Care Medicine, University of Calgary. “Despite the challenges in monitoring and limiting the spread of SARS-CoV-2 so far, many people are likely still susceptible to infection, which means that future spikes are possible. We need to continue adhering to public health measures, ensure equitable distribution of vaccines, and improve confidence in vaccination.”
“Last year, on average, studies around the world reported about 4.5% seroprevalence, meaning only 4.5% of people had antibodies to SARS-COV-2, suggesting a previous infection. Antibody tests can capture infections missed by diagnostic testing to give us a more accurate picture of the pandemic’s spread,” explains Rahul Arora, co-lead author and Adjunct Lecturer, Department of Community Health Sciences, University of Calgary. “Seroprevalence studies therefore estimate the number of people with some form of immunity to SARS-CoV-2, the virus that causes COVID-19, although it’s still unclear how long that immunity lasts.”
Compiling data from these global surveys provides insight on variations with which jurisdictions have tracked the pandemic with diagnostic testing. “We found important differences when comparing infection rates from diagnostic testing, which indicates acute infection, and antibody data, which indicate previous infection. In some areas of the world, there were six times more infections identified using antibody results than reported by diagnostic testing. This indicates there has been substantial infection spread not captured by reported case counts, likely due to a slow ramp-up of diagnostic testing in some cases, or inequitable access to it,” says Dr. Matthew Cheng, Assistant Professor, McGill University, Scientific Advisor for the CITF and co-senior author on the article.
The study also highlights major inequities in the pandemic impact and response. “Although antibody prevalence was low in the general population, there were significant differences in infection burden when stratified by demographics. Infection rates were higher in Black, Asian, and Indigenous people – indicating the need to prioritize protecting the hardest-hit populations through vaccine, workplace and community efforts,” says Rahul Arora. “Additionally, only 23% of the studies were conducted in low- and middle-income countries. The global community needs to come together to bolster pandemic preparedness and accessibility to research and public health tools.”
“This study serves as a vital baseline measurement of the world’s burden of infection, pre-vaccination, and highlights the imperative of equitable access to vaccines to bring the COVID-19 pandemic under control everywhere,” says Dr. Tim Evans, Executive Director of the COVID-19 Immunity Task Force and a co-author of the study.
As the pandemic persists, the group plans to continue harnessing antibody data to inform the public health response. Beyond the systematic review, SeroTracker’s database and dashboard continues to evolve. On the website, new results are being uploaded weekly. The WHO, Gates Foundation, McKinsey, Forbes and New York Times, among others, have used the dataset to inform their work.
“SeroTracker has created a method for rapid synthesis of real-world data that has informed science, investments, and policy-making in multiple aspects of the pandemic response, such as calculating infection fatality and identifying optimal vaccine trial sites,” says Arora. “Our long-term vision is to use data to enable rapid, effective, and equitable responses to pandemics. We are exploring the adaptability of our data platform to achieve this.”
SeroTracker is a dashboard and data platform for COVID-19 antibody testing studies, or serosurveys. The platform is a global collaboration of over 20 researchers, engineers, and physicians from six universities in Canada, the UK, and the United States. SeroTracker is funded by the Government of Canada through its COVID-19 Immunity Task Force, as well as by the World Health Organization, and the Canadian Medical Association. Visit the interactive dashboard at https://serotracker.com/en/Explore.
About the COVID-19 Immunity Task Force
The Government of Canada established the COVID-19 Immunity Task Force in late April 2020. The Task Force is overseen by a Leadership Group of volunteers that includes leading Canadian scientists and experts from universities and healthcare facilities across Canada who are focused on understanding the nature of immunity arising from the novel coronavirus that causes COVID-19. To that end, the CITF is supporting numerous studies to determine the extent of SARS-CoV-2 infection in Canada (in the general population as well as in specific communities and priority populations), understand the nature of immunity following infection, develop improved antibody testing methods, and help monitor the effectiveness and safety of vaccines as they are rolled out across Canada. The Task Force and its Secretariat accordingly work closely with a range of partners, including governments, public health agencies, institutions, health organizations, research teams, and other task forces, and engage communities and stakeholders. Most recently, the Task Force has been asked to support vaccine surveillance, effectiveness, and safety as part of its overall objective to generate data and ideas that inform interventions aimed at slowing—and ultimately stopping—the spread of SARS-CoV-2 in Canada. For more information visit: www.covid19immunitytaskforce.ca
COVID-19 Immunity Task Force
Rebecca Burns, Cell: +1.438.871.8763