Canada’s top doctor warns against relying on herd immunity to reopen economy

Chief Public Health Officer Theresa Tam said Saturday that it's 'premature' to place too much stock in immunity testing — and issuing passes to re-enter society —based on someone's level of protection.

Canada’s top doctor says there isn’t enough evidence to back herd immunity as a way to reopen society, as Quebec’s premier is considering the approach to restart his province’s economy.

“The idea of … generating natural immunity is actually not something that should be undertaken,” Canada’s Chief Public Health Officer Theresa Tam said Saturday, urging people to be “extremely cautious” about the concept.

Herd immunity is conferred when enough people in a given population have been infected with a virus, marking them immune to reinfection and slowing down the rate at which the virus spreads on its own.