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We Asked Experts About COVID-19 Vaccine Boosters In Quebec — Here's What They Said

Pro: Boosters add protection as immunity wanes and variants emerge. Con: This story doesn't end soon.

Deputy Editor
We Asked Experts About COVID-19 Vaccine Boosters In Quebec — Here's What They Said

As conversations and concerns about the Omicron COVID-19 variant grow, talk of additional boosters has also picked up. In the U.S., a third dose is available for everyone 16 and older. Here in Quebec, the government has slowly been expanding eligibility for a third dose.

So what should we know about boosters? We asked the experts.

Why do we need them?

"The issues are that the vaccines are not 100% effective (no vaccines are) and immunity seems to wane in time," Dr. Mark Goldberg, an environmental epidemiologist and professor in the department of medicine at McGill University, said in an email to MTL Blog.

"New variants are reducing effectiveness of the current vaccines so a third dose will help."

Quebec hasn't yet rolled out third doses for the overall population — is this a concern?

Quebec's early decision to space out first and second doses was done to get more first doses into Quebecers' arms while vaccines were in short supply. But that move ended up having a positive but unintended consequence, said Dr. Anne Gatignol, a professor of immunology and microbiology at McGill University.

"A delay between 8 to 11 weeks is the best to acquire more antibodies (about 3 times more) and a better immunity. Therefore, we are better protected than most countries who had a 3-4 week delay."

The decline in immunity from the vaccines is also faster among older people, Gatignol said, so younger people shouldn't need boosters as urgently as the elderly. For people over 80, she said, immunity begins to decline after around six months. But for people over 50, the decline doesn’t start until around nine months.

OK, but what about Omicron?

That part is still fuzzy. Scientists are still figuring out the implications of Omicron, but it seems clear that it's going to mess up existing assumptions and plans around COVID-19.

Existing vaccines appear to provide partial protection that's beefed up with a booster shot, said Gatignol.

"Depending on how virulent Omicron turns out to be (it looks much more infectious than Delta), we may see new targeted vaccines in the spring," wrote Goldberg. ( In a news release, Pfizer and BioNTech said they could have an Omicron-specific vaccine ready by March.)

Are we going to need boosters forever?

It's possible. Evidence suggests that immunity to coronaviruses, like with viruses that cause colds, wanes with time, Gatignol said. She and Goldberg both said they expect that eventually there may be an annual COVID-19 booster, like we already have for the flu.

The bad news, Goldberg said, is the massive variation in vaccination rates around the world.

"The problem is that unless the world is immunized we should expect new variants, and these can potentially be very virulent and may evade our defences. Giving boosters in the developed countries reduces supply elsewhere and neither the companies nor countries are doing what is needed to increase the supply to the rest of the world. Unless we do this, expect this pandemic to go on for years."

What should we do now?

The usual, the experts said: get vaccinated, wear a mask, keep gatherings small, wash your hands.

If you’re younger and healthy, there's "no need to rush on the third dose" for now, said Gatignol, but watch out for new recommendations as more is learned about Omicron.

Those who haven’t gotten vaccinated yet or who have only had one dose should get their shots ASAP, Gatignol and Goldberg both said.

If you’re unvaccinated, Goldberg said, "You are playing Russian roulette with your health and those of your loved ones, friends, and colleagues. This disease is serious: it kills and it can cause serious disability and long term health problems."

Health Canada has a robust website with all the latest information on COVID-19 vaccines and can answer any questions you may have.

This article's cover image was used for illustrative purposes only.

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