As Canada’s vaccination numbers continue to increase, many people are starting to wonder how long we’ll stay protected. Will we be regularly getting booster shots to protect against COVID-19, the same way we get the flu vaccine every year?
Here are answers to some of the most common questions about the potential COVID booster shot.
What exactly does a booster shot do?
Boosters strengthen the immune system by stimulating our bodies’ B-cells, which produce new antibodies. The booster works by triggering the memory of the original vaccine in some B-cells, which causes the body to kickstart producing the necessary antibodies again.
Booster shots can be especially helpful for vulnerable populations — elderly people and people who are immunocompromised, for instance.
“People who are immunocompromised do generate lower antibody levels and they decline faster over time,” Dr. Allison McGeer, an infectious disease specialist at Mount Sinai Hospital in Toronto, told CBC News. In other words, they’re the people who could benefit most from a booster shot.
Do we need COVID booster shots?
The drug companies say yes — but so far, health authorities have said it isn’t necessary for the general public yet.
In the spring, Moderna released results from a study that found booster shots were effective in increasing immunity against new variants of the virus, such as the P.1 or Gamma variant, and B.1.351, now known as the Beta variant. (It’s worth noting, though, that this is early data from a small trial.) And Pfizer and Johnson & Johnson have both said it’s possible that people will need annual COVID vaccine boosters, similar to the way we get yearly flu shots.
The big issue is that scientists don’t know yet how long the immunity provided by the vaccine will last.
Health Canada has said research shows people are protected up to 9 months after their second dose. But research from Washington University School of Medicine in St. Louis, Missouri has indicated that the mRNA vaccines — Pfizer and Moderna — could provide immunity for years.
“It’s a good sign for how durable our immunity is from this vaccine,” immunologist Ali Ellebedy, who led the study, told The New York Times.
Will we get boosters in Canada?
Maybe — but not yet. Health Canada said Friday that “the need for future booster doses is being closely monitored,” given the new virus’s new variants, but that there aren’t any immediate plans for a booster rollout.
“Emerging data to date shows good immunity in most people out to 9 months after receiving 2 vaccine doses,” the agency said. “It is possible that Canadians will need a subsequent vaccination, or booster shot, after we have reached sufficient levels of community protection with the current rollout.”
While Pfizer has asked regulators in the U.S. and Europe to approve a COVID booster, the company hasn’t approached Health Canada with the same request, Health Canada added.
What about other countries?
Israel, dealing with high infection numbers from the Delta variant, said Sunday it will start offering booster shots, first to immunocompromised people, Health Minister Nitzan Horowitz said, and will decide at a later day if the booster policy will extend to the general population.
The U.K. has started planning a booster rollout beginning this fall, although the government has not yet made a final decision to go ahead yet. The plan involves starting with people who live in long-term care facilities, are immunocompromised, or are above 70 years old.
In the U.S., there’s no immediate plan to make boosters happen. Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, essentially said the same thing as the Canadian authorities: maybe later, but not yet.
“Right now, given the data and the information we have, we do not need to give people a third shot,” Fauci told CNN on Sunday. It’s possible that later on, boosters will be encouraged, he said, but for now, they haven’t been deemed necessary.
Would the booster shot be the same vaccine for a third time?
Maybe. Moderna’s booster research has tested both its existing formula and a new version designed to combat the Beta variant, and said both were effective against the strain.
Some scientists have said they can foresee a future where regular boosters are tailored against new variants, to provide protection against strains that hadn’t been identified when the initial vaccines were being made.
“Anything that would actually require a booster would be variant-based, not based on waning of immunity,” immunologist D. Deepta Bhattacharya predicted in the New York Times.
Does it make sense to focus on boosters when much of the world hasn’t had a single dose?
Many experts say no — including Dr. Tedros Adhanom Ghebreyesus, director general of the World Health Organization.
“Some countries with high vaccination coverage are now planning to roll out booster shots in the coming months,”he said at a press conferencelast week.
“Vaccine nationalism, where a handful of nations have taken the lion’s share, is morally indefensible and an ineffective public health strategy.”
Like Ghebreyesus, some doctors are saying that, in addition to the ethical considerations, giving boosters to wealthy countries when so much of the world can’t access first doses is actually dangerous for everyone.
Montreal’s Dr. Caroline Quach-Thanh, former chair of the National Advisory Committee on Immunization (NACI), believes global vaccination should be Canada’s priority.
“If you give those [third] doses here, it means that you’re not giving them elsewhere,” she told CBC. “At this point in time, what is absolutely needed is for the entire planet to be vaccinated, because if we want to stop the emergence of all those variants of concern that we’re seeing like day in, day out, we absolutely need to have everyone vaccinated.”
As WHO advisor Dr. Peter Singer put it, “to be safe is for this fire to be put out everywhere in the world.”
Otherwise, he told Global News, “if it’s burning anywhere, it’s going to be casting off embers that are going to ignite flames everywhere.”