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.

https://www.cbc.ca/news/health/covid-19-masks-convincing-1.5638205