VANCOUVER -- A test that can determine whether someone has been exposed to COVID-19 by detecting antibodies in their blood has now been approved by Health Canada.

At the same time, British Columbians are now being asked if they’d be willing to take part in future antibody testing. The question is included at the end of a wide-ranging survey polling people about the effects of the pandemic on their lives.

It’s hoped the antibody testing can help provide further understanding about whether people who have been infected have immunity to the virus, and how long that protection may last.

On Wednesday, Health Canada announced they have formally approved a test called the Liasion analyzer, manufactured by DiaSorin, an Italian multinational biotech company. At least one million blood samples are expected to be collected and tested in Canada over the next two years. The same test has also been approved in the U.S.

UBC adjunct professor in the Division of Infectious Diseases Dr. Horacio Bach told CTV News Vancouver this specific test measures an antibody that appears around two weeks after symptoms appear.

“We know some that people, they may have the virus but don’t show symptoms. Some of them are very mild, and can be confused with a regular flu. So at least this test can tell you exactly if you were exposed or not,” Bach said. “It’s a very strong tool to monitor the propagation or expansion of the virus in the community.”

Provincial health officer Dr. Bonnie Henry said the Liasion is one of the tests that B.C. had been “validating," and added she expects there will be more approved in the coming days.

“By the time we get to the fall, I’m hopeful we’ll have more information about what it means when you have antibodies,” Henry said. She cautioned there are caveats, including that the tests are not 100 per cent accurate.

“We still have a problem when there’s low levels in the community of having false positives, and false negatives, so that’s something we need to build into the protocols that we’re using,” she said.

In addition, it’s still unknown how long COVID-19 antibodies last in the system, and what level is required to provide immunity.

Deputy provincial health officer Dr. Reka Gustafson said for some types of infections, it’s possible to measure the amount of antibodies to understand how likely a person is to have immunity. But COVID-19 is new.

“We do believe there’s likely to be some degree of immunity. But the length of it, and the strength of it is something that is yet to be confirmed,” Gustafson said.

The B.C. COVID-19 survey, which is open to British Columbians 18 and older until May 31, also gives respondents the chance to indicate whether they would be willing to take part in future testing for antibodies, to determine immunity in the population.

“We know that serological testing will have a role in our response to COVID-19,” Gustafson said. “And so we thought that this was a really good opportunity to ask people whether they would be interested in participating in that with us.”

Gustafson stressed the primary goal of the survey is about understanding how people are faring overall in the pandemic. Over 75,000 people had responded to the survey as of noon Wednesday, according to the provincial health officer.

As for when antibody testing could begin, Gustafson said she expected it would start relatively soon.

“There’s a great deal of interest and the consequences are very big,” she said. “Understanding how we can live with COVID-19 depends on our understanding of immunity, of protection.”