An AbCellera Biologics Inc. scientist pipettes cell culture reagents in a biosafety cabinet at an AbCellera laboratory in this undated handout photo. As researchers race to develop a vaccine, the head of a Vancouver biotech company says another valuable shield against COVID-19 could work better and buy time in the interim. THE CANADIAN PRESS/HO, AbCellera Biologics Inc.

Serological surveys to look for COVID-19 immunity in Canadian population

It’s not yet known how much immunity antibodies can offer

Canada’s top doctor says too little is known to consider using a newly approved serology test to identify individuals who could be immune to COVID-19 and allow those people to return to work or gather in public.

Instead, Theresa Tam said Wednesday that the new LIAISON test will be used more broadly to look for immunity in the Canadian population, noting questions persist about the prevalence of COVID-19 antibodies and what protections they offer.

Tam said an immunity task force had been formed to examine what protection from reinfection exists among those who have recovered from COVID-19.

“Now that you have the first test, we’re hoping to see rapid implementation of the actual population surveys, both general and those focusing on specific communities, geographies, (and) occupational groups,” said Tam, Canada’s chief public health officer.

“They’re working as fast as they can and hopefully this will be quite rapid in terms of its rollout.”

The comments came a day after Health Canada said it had authorized the first serological test to detect antibodies specific to the virus that causes COVID-19.

READ MORE: Health Canada approves serological test to detect COVID-19

The federal agency said Tuesday that at least one million Canadian blood samples will be collected and tested over the next two years to track the virus in the general population and in specific groups at greater risk of having been infected, including health-care workers and seniors.

Even if a test has been authorized, Tam said Health Canada must monitor its ability to perform in real-life applications.

“How specific are they? Can they actually detect the specific COVID-19 antibodies or not?” said Tam.

“All of that remains to be seen which just means that we need to evaluate and monitor these tests as carefully as we can.”

Unlike the current PCR diagnostic tests that tell us where COVID-19 is presently, serology tests reveal if someone has been infected in the past and has developed antibodies to the virus.

Experts say that can give us a better sense of how prevalent infection has been and how to further prevent COVID-19 spread — information that is critical as various regions of the country begin to reopen.

Nova Scotia’s chief medical officer of health noted Wednesday that serology tests could provide good information on the role asymptomatic people play in community spread.

“Nationally, there is discussion about doing a sero-survey. So you do a sample of people across the country, big enough that you can get representative numbers from each of the provinces and territories. Through that, you get a sense of how many people have been actually immune from wave one, and then we could match that up with a number of known cases we have,” said Dr. Robert Strang.

“And the difference would give us an estimation of the number of people that weren’t recognized — either they were asymptomatic or never came forward for testing.”

At the other end of the country, B.C.’s provincial health officer has already invited residents there to volunteer for a serology blood testing study.

Dr. Bonnie Henry announced the study Tuesday, along with a survey to gather information about how people have been affected by COVID-19 measures.

READ MORE: B.C. begins broad COVID-19 survey, with option for antibody testing

Patrick Saunders-Hastings, an epidemiologist and consultant with the management consulting firm Gevity Consulting Inc., said one issue with serological tests in general has been their reliability.

He agreed that the goal should be to try to determine on a broad scale who has antibodies that may protect them from the coronavirus rather than aim for individual immunity passports.

“Serological testing performance is quite variable,” said Saunders-Hastings, director of life sciences and environmental health at the firm.

“And when we do get down to the individual levels some of the sort of false positives and false negatives can be quite problematic.”

He added that serology should be used as a complement to ongoing clinical diagnostic testing, which would identify current infections.

Also unknown: the amount of antibodies needed to confer full immunity and how long immunity lasts.

Tam said it was too early to discuss the possibility of so-called immunity passports, which the World Health Organization has cautioned against.

“We really we need more information.”

Cassandra Szklarski, The Canadian Press


Like us on Facebook and follow us on Twitter.

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

Coronavirus

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

Just Posted

Ucluelet senior grateful after trespassers apologize

“It gave me some of my dignity back,” said Ellen Kimoto of Spring Cove.

Tofino’s Crystal Cove crowned top family destination for second year in a row

TripAdvisor has announced the recipients of its Travelers’ Choice Best of the Best awards.

COVID-19: Tla-o-qui-aht First Nation asks Tofino businesses for support as emergency funding runs dry

“We need to pay for the work they do. It’s such important work.”

DFO says the five aggrieved B.C First Nations were consulted on fisheries plan

Nuu-chah-nulth First Nations calls response ‘a sham,’ adding DFO never incorporates their views

Three active COVID-19 cases on Vancouver Island

Since July 24, Central island has had five new cases, North one, South none

‘Don’t kill my mom’: Ryan Reynolds calls on young British Columbians to be COVID-smart

‘Deadpool’ celebrity responds to premier’s call for social influence support

Captain Horvat’s OT marker lifts Canucks to 4-3 win over Blues

Vancouver takes 2-0 lead in best-of-7 NHL playoff series with St. Louis

Widow of slain Red Deer doctor thanks community for support ahead of vigil

Fellow doctors, members of the public will gather for a physically-distanced vigil in central Alberta

Protesters showcase massive old yellow cedar as Port Renfrew area forest blockade continues

9.5-foot-wide yellow cedar measured by Ancient Forest Alliance campaigners in Fairy Creek watershed

Taking dog feces and a jackhammer to neighbourhood dispute costs B.C. man $16,000

‘Pellegrin’s actions were motivated by malice …a vindictive, pointless, dangerous and unlawful act’

Racist stickers at Keremeos pub leaves group uneasy and angry

The ‘OK’ hand gesture is a known hate-symbol

VIDEO: World responds to B.C. girl after pandemic cancels birthday party

Dozens of cards and numerous packages were delivered to six-year-old Charlie Manning

Expected fall peak of COVID-19 in Canada could overwhelm health systems: Tam

National modelling projections released Friday show an expected peak in cases this fall

Most Read