First glimpse of Canada’s true COVID-19 infection rate expected mid-July

First glimpse of Canada’s true COVID-19 infection rate expected mid-July

First glimpse of Canada’s true COVID-19 infection rate expected mid-July

OTTAWA — The national immunity task force has started testing thousands of blood samples for COVID-19 antibodies and should be able to produce a more detailed picture of how many Canadians have been infected with the novel coronavirus within a couple of weeks.

It will be much longer, however, before we know more about what kind of protection against future infection having the antibodies provides, said Dr. Timothy Evans, executive director of the COVID-19 Immunity Task Force.

Plus, said Evans, most of the people whose blood is being tested will not be informed of the results because of how the blood is being collected for testing.

“There won’t be an opportunity for individuals to find out their status,” said Evans, who is also director of the McGill School of Population and Global Health.

At least 105,000 Canadians have tested positive for COVID-19 since the coronavirus was identified in January, while many others were sick but couldn’t get tested because provinces were limiting who could access the procedure until just a few weeks ago.

Evans also said a significant number of people get the infection and show no symptoms and will have no clue they were ever sick. Evans said immunity testing in other countries has suggested the actual infection rate is 10 to 20 times more than the number of confirmed cases.

There are multiple prongs to the task force’s plan to figure out the true infection rate here, starting with running antibody tests on 40,000 samples collected from people who donated blood to Canadian Blood Services and Hema Quebec since May. Evans said about 1,600 of those samples are being run through the test kits every day now, and analyses are already under way on the results.

“Hopefully within the next two weeks we will have an initial first number,” he said.

The first results will reveal how many samples showed antibodies, but include no specifics like whether they are male or female or where they live.

“By the end of the month of July, we expect to have a more broken down picture of what we call the seroprevalence, the presence of antibodies in the blood, that will look at it by age group and geographic location,” Evans said.

Evans said Canadian Blood Services can’t trace back the samples to the actual patients who gave them, so positive antibody tests will not be reported back for anyone who donated blood outside of Quebec. He said Hema Quebec said it might be possible to identify the patients but hasn’t yet decided if it will do so.

Another testing program is now beginning on 25,000 blood samples taken from pregnant women, using blood routinely drawn during the first trimester to screen for sexually transmitted infections and check for immunity to other illnesses like rubella. COVID-19 antibody testing will be added to that list for all pregnant women in Canada, going back all the way to December. The women will be informed if they test positive for COVID-19 antibodies, said Evans.

Evans said there are also about 30,000 blood samples held in provincial labs that are being tested for antibodies.

He said together these projects can provide a piecemeal picture of the infection rate across the country, though it won’t be a truly representative sample until a national household survey can be run. That isn’t going to happen until the portable antibody tests become reliable, but a plan is being developed with Statistics Canada so it’s ready when the tests are.

“We’d love to have a test that didn’t require a formal blood draw, but rather a pin prick but we’re not quite there yet,” he said. “There’s some things on the horizon. We’re trying to get those validated quickly but we still haven’t got what I would call a good portable test that could be used in the home.”

The tests the task force is using now require only a small amount of blood — less than 1/20th of a teaspoon, generally — but it is still more than what comes from a finger prick.

Evans said understanding how many people got infected can help drive policy decisions about where to vaccinate first, the impact specific public health measures might have had in some settings like long-term care centres, hospitals and schools, or communities that have been hit particularly hard.

The task force also has a two-year mandate to try to look at what kind of protection someone has from having antibodies, as well as how long the levels of antibodies last in a person’s blood. Evans said those studies are just getting underway and will take time, including looking to see whether people who have the antibodies get infected during a second or third wave of the pandemic.

This report by The Canadian Press was first published July 5, 2020.

Mia Rabson, The Canadian Press

Coronavirus

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

Just Posted

(Contributed)
Red Deer Regional Health Foundation receives $40K in donations

Donations from Canadian Pacific and Durham family of Red Deer

NDP MP Heather McPherson pictured in Edmonton on Friday, March 6, 2020. Alberta’s legislature may have been silenced but its partisan warfare has relocated to the House of Commons as MPs hold an emergency debate tonight on the province’s soaring COVID-19 cases. THE CANADIAN PRESS/Jason Franson
Kenney under fire during Commons emergency debate on Alberta’s COVID-19 crisis

Edmonton New Democrat MP says Kenney ignored the evidence of science

A General Motors sign in Oshawa, Ont., is photographed on Wednesday, June 20, 2018. General Motors Canada says it will start truck production at its assembly plant in Oshawa, Ont., ahead of schedule. THE CANADIAN PRESS/ Tijana Martin
Oshawa assembly plant restart ahead of schedule, GM Canada says

Closure of plant in 2019 was huge blow to Canada’s manufacturing sector

FILE - In this Jan. 24, 2019, file photo, a woman walks by the Australian Embassy in Beijing. China on Thursday, May 6, 2021 suspended an economic dialogue with Australia, stepping up a pressure campaign that began over Australian support for a probe into the origins of the coronavirus. (AP Photo/Andy Wong)
China suspends economic dialogue with Australia

China’s relations with Australia, India and some other neighbours are increasingly strained

LtE bug
Letter: Restrictions are a crime against humanity

I was distressed to note the seemingly superficial understanding of the holocaust… Continue reading

LtE bug
Letter: Follow restrictions so pandemic can be behind us

From one who feels that COVID could have been overcome long ago… Continue reading

LtE bug
Letter: Westerner needs help now

I have spent the last few days sifting through many pieces of… Continue reading

Jets beat Flames 4-0 to snap seven-game losing streak and clinch playoff spot

Jets beat Flames 4-0 to snap seven-game losing streak and clinch playoff spot

Most Read