A blood donor clinic pictured at a shopping mall in Calgary, Alta., Friday, March 27, 2020. Fewer than 1 per cent of Canadian blood donors in late spring tested positive for COVID-19 antibodies, according to the results of a seroprevalence study that aimed to assess the country’s infection rate of the novel coronavirus. THE CANADIAN PRESS/Jeff McIntosh

Study shows fewer than 1 per cent Canadian blood donors had COVID antibodies

Researchers say antibodies indicate past infection

Fewer than 1 per cent of Canadian blood donors in late spring tested positive for COVID-19 antibodies, according to the results of a seroprevalence study that aimed to assess the country’s infection rate of the novel coronavirus.

Canadian Blood Services and Canada’s COVID-19 Immunity Task Force (CITF) released the findings of the study on Tuesday, based on 37,373 blood samples collected from blood donor centres across Canada except Quebec and the Territories from May 9 to June 18.

The results suggest that by the end of May as few as 0.7 per cent of healthy Canadians had been exposed to SARS-CoV-2, the virus causing COVID-19.

Researchers say antibodies indicate past infection, and can usually be detected within two weeks of the onset of infection.

However, they say the results of the study could underestimate “true seroprevalence” for a number of reasons.

Professor Catherine Hankins, the co-chair of CITF, says antibody levels decline rapidly, and “may have disappeared in some people by the time of testing.”

Hankins also says blood donors are typically more ”health-conscious and healthier” than the general population.

CITF co-chair David Naylor says the current increasing number of COVID-19 cases nationwide suggests a need for continued vigilance.

And while health experts are still unclear on how much, if any, immunity antibodies might provide, Naylor says there is “little to no likelihood” that immunity levels in the population are “high enough to slow down a second wave of COVID-19 infection.

“It’s critical to ramp-up testing and tracing capacity across the country to reduce risk in settings such as workplaces and schools, and to interrupt any chains of transmission quickly to prevent spread,” he added.

The results of the study were broken down by province, showing that P.E.I. and New Brunswick had the lowest seroprevalence at 0 per cent and 0.26 per cent, respectively. Ontario showed the highest with 0.96 per cent.

Quebec’s Hema-Quebec ran its own study on blood donors in the province, which showed the highest seroprevalence in the country at 2.23 per cent.

In individual cities, Ottawa showed the highest percentage of SARS-CoV-2 antibodies with 1.29 per cent seroprevalence, Toronto had 1.07 per cent and Edmonton had 0.38 per cent.

Montreal and Laval showed a seroprevalence of 3.05 per cent in the Hema-Quebec study.

Dr. Graham Sher, CEO of Canadian Blood Services, says its donor base is ”reasonably representative of healthy Canadians between the ages of 17 and about 60.”

READ MORE: B.C. records 429 new COVID-19 cases, two deaths over Labour Day long weekend

The Canadian Press


Like us on Facebook and follow us on Twitter.

Want to support local journalism during the pandemic? Make a donation here.

blood donorCoronavirus

Get local stories you won't find anywhere else right to your inbox.
Sign up here

Just Posted

Cops For Kids ride wraps in Okanagan

No pomp, no circumstance for end of milestone 20th anniversary fundraising bicycle trip

Former Kelowna cop faces fourth lawsuit alleging sexual assault

Ex-Mountie Brian Mathew Burkett is also separately facing seven charges of breach of trust

QUIZ: A celebration of apples

September is the start of the apple harvest

Smoky skies clearing throughout B.C. Interior

Environment Canada expects “widespread” improvement for all affected areas by Sunday

B.C. or Ontario? Residential school survivors fight move of court battle

It’s now up to Ontario’s Court of Appeal to sort out the venue question

B.C. transportation minister will not seek re-election

Claire Trevena has held the position since 2017

Squabble over mask policy at LUSH in Kelowna mall

The woman filmed the encounter at LUSH Cosmetics, where wearing a mask in-store is company policy

Province opens ‘middle income’ housing in Kelowna

Prices on the units are $1,300 for a one-bedroom and $1,780 for a two-bedroom, nearing area-average prices

Is it time to start thinking about greener ways to package cannabis?

Packaging suppliers are still figuring eco-friendly and affordable packaging options that fit the mandates of Cannabis Regulations

Young B.C. cancer survivor rides 105-km with Terry Fox’s brother

Jacob Bredenhof and Darrell Fox’s cycling trek raises almost $90,000 for cancer research

B.C. migrant, undocumented workers rally for permanent residency program

Rally is part of the Amnesty for Undocumented Workers Campaign led by the Migrant Workers Centre

Reward offered for return of Okanagan puppy

An 11-week-old boxer-mastiff cross pup was allegedly taken from its Kelowna Friday, Sept. 18

Preparations underway for pandemic election in Saskatchewan and maybe B.C.

Administrators in B.C. and around the country are also looking to expand voting by mail during the pandemic

Most Read