New study offers first glimpse into COVID-19 antibodies in Canada’s adult population
Initial results indicate fewer than 1 in 100 blood donations have antibodies to the novel coronavirus that causes COVID-19
MONTREAL, OTTAWA, and TORONTO — On July 23, Canadian Blood Services and Canada’s COVID-19 Immunity Task Force (CITF) released results of the first 10,000 blood donor samples assessed for SARS-CoV-2 antibodies.
This analysis reveals that over the period from May 9 through June 8, 2020, fewer than 1% of the 10,000 samples from blood donors tested positive for antibodies to the novel coronavirus. Antibodies indicate past infection with SARS-CoV-2, and population studies like this one tell us how many people have likely been exposed to the virus.
These results offer a first glimpse into an ongoing Canadian Blood Services study assessing SARS-CoV-2 antibodies across nine provinces. They will be updated once Canadian Blood Services completes their analysis of the full sample of 37,800 donations made during the months of May and June 2020.
In addition, Héma-Québec will have results for Quebec in the near future, which will be important for a complete national picture, given the COVID-19 rates in that province.
While there will be adjustments to this initial figure once the full 10-province study is completed, professor Catherine Hankins, CITF co-chair, said its implications bear public attention immediately, as reopening is causing an uptick in COVID-19 cases across Canada.
“What is clear is that only a small percentage of adult Canadians has been infected by SARS-CoV-2,” Hankins said in a statement. “By far, the majority of us remain vulnerable to infection. We need to ramp up testing and tracing capacity across the country to interrupt any chains of transmission quickly to prevent unchecked spread.”
Acknowledging that many more adult Canadians are infected than currently documented, Timothy Evans, CITF executive director cautioned against over-interpreting the apparent reduction in risk.
“Among adults, the death rate from being infected with SARS-CoV-2 is likely closer to 1%, as compared to the eight per cent reported to date among those diagnosed with COVID-19,” Evans said. “But this is a highly infective virus that could take a huge toll if we allow it to spread, and we are only now learning that many survivors have persistent symptoms.”