Canada needs to make a tough call on boosters as a new variant emerges

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Despite a growing push to roll out COVID-19 vaccine boosters more widely in Canada, epidemiologists say there is currently no evidence of an urgent need for additional shots in the general population — due to the strong, ongoing protection two doses already provide.

But with the emergence of the potentially more infectious omicron variant, the holidays rapidly approaching and COVID-19 levels remaining elevated in much of the country, should Canada wait for more proof of waning immunity before expanding eligibility of boosters?

Or should we move quickly to offer up additional shots to fend off another potential surge as the U.S., the U.K. and Israel have done?

Some provinces and territories have already expanded access to boosters — including Manitoba, the Northwest Territories and Yukon — while others have taken a more cautious approach by only offering them to certain vulnerable groups and health-care workers.

But the current case for rolling out third shots to most Canadians while much of the world remains unvaccinated and new variants continue to emerge seems weak at best.

"There is currently no evidence of widespread decreasing protection over time against severe disease in the general Canadian population who have been vaccinated," a spokesperson for the National Advisory Committee on Immunization (NACI) told CBC News. 

"NACI continues to actively review available evidence from Canada and other countries, and if needed, will update advice on booster doses as a preventive measure."

Experts are divided over the need to expand access to additional shots to more Canadians — or even to everyone over 18 — and the emergence of the omicron variant will likely only heat up the debate further until we know more about it.

"I understand that mounting pressure to give more and more doses," said Dr. Danuta Skowronski, epidemiology lead at the British Columbia Centre for Disease Control, whose research prompted Canada's decision to delay second doses of COVID-19 vaccines. 

"But I cannot say based on the current evidence that there is a clear and present danger or need or indication for an additional dose for the general population of adults at this time."

Skowronski said the latest data from B.C. and Quebec, released jointly as a recent preprint study that has yet to be peer reviewed, suggested mRNA vaccines were close to 95 per cent protective against hospitalization and over 80 per cent against any infection.

"Should we be attempting a preemptive strike to fend off a possible surge? Well, that kind of attitude is a slippery slope," she said.

Rolling out boosters more widely is a "massive population-wide undertaking" that could set a bad precedent for future shots.