Canadian Blood Services and the COVID-19 Immunity Task Force have been monitoring exposure and their findings suggest 1.5 per cent of healthy Canadians had been exposed to the virus causing COVID-19. Their study is based on 33,860 blood samples from blood donor centres across Canada, excluding Quebec and the Territories, collected in October and November 2020

Task Force Executive Director Tim Evans says, although this represents a doubling in comparison to an initial report following the first wave in May and June, the overall number of people with antibodies, which suggests a previous COVID-19 infection, remains very low and Canada remains a long way from herd immunity.

The results show the greatest increases in the Prairies and Western provinces. Dr. Sheila O’Brien, associate director of epidemiology and surveillance at Canadian Blood Services says, “Since the first wave in May and June, exposure in Manitoba and Saskatchewan increased five-fold, from 1.69% to 8.71%.”

Dr. Catherine Hankins, Task Force Co-Chair says, “It is clear that the vast majority of Canadians remain vulnerable to COVID-19.” She says, “We have no choice but to keep up public health measures until vaccine-induced immunity grows substantially.”