COVID-19 in Canada: The 'key' to vaccine coverage to protect Canadians against variants of concern

With the Delta variant of COVID-19 Dr. Theresa Tam, Canada’s chief public health officer, stressed that even higher vaccination coverage is needed to protect against hospitalizations and overwhelming the health system.

"It comes down to our bottom line, which is two doses, now, are better than one," Dr. Tam said. "Aiming for that 75 [per cent of the population with their first dose], 75 [per cent of the population with their second dose] is actually the key in terms of vaccine coverage for us to have the kind of community level of resilience, if you like, against variants of concern that are more transmissible."

"Should we aim for higher? Yes, I think we should. Shoot for higher...shoot for the stars, that gives us a better buffer for managing the COVID-19 situation."

With a variant like Delta that seems to have an increased risk of hospitalization, two doses are ideal to protect against infection and symptomatic infection.

In terms of which mRNA vaccine Canadians should get, Dr. Tam indicated she does support mixing first and second doses, based on supply.

"I think the most important thing is to get that second dose," she said. "Depending on where you are and what the supply situation is, if the second dose of mRNA vaccine is the other one...that is OK as well."

"Both target the same spike protein, that is really important and they’ve performed in really fairly similar ways when you look at the clinical outcomes."

As provinces enter various stages of reopening plans, Canada's chief public health officer stressed that restrictions should be eased cautiously, in stages, and with an interval in between each steps to monitor for any changes in virus patterns.