You might want to wait until fall for your next COVID-19 shot, doctors say. Here's why

Health Canada told CBC News they'll finish reviewing updated COVID vaccines by "early autumn" on the heels of the U.S. approving two updated vaccines to protect against hospitalizations and deaths. 

As COVID looms over the Paralympic Games in Paris that start Wednesday following outbreaks among Olympic athletes, new subvariants of Omicron continue to ebb and flow and make people ill. Doctors and public health experts want people to consider getting immunized as part of their fall plans. 

Mandy Cohen, director of the U.S. Centers for Disease Control and Prevention, told reporters on Aug. 22 why officials think the updated vaccines are important. 

"While the COVID virus continues to mutate and change faster than the flu virus, our underlying immunity from prior vaccines and prior infections provides some protection," Cohen said. "But we know that protection decreases over time, and certain groups continue to be at higher risk from COVID and other viruses, and we need to continue to protect ourselves and our loved ones."

Dawn Bowdish, an immunology professor at McMaster University in Hamilton, Ont., said COVID activity tends to peak every three to six months, such as in this coming winter. 

What variants are in the upcoming vaccine? 

Along with the Omicron subvariants currently circulating in Canada and the U.S., KP variants that are offshoots of Omicron started spreading rapidly around the world in late 2021. 

Vaccine makers and regulators like Health Canada are now gearing up to get the latest protection into arms. 

"Health Canada is reviewing submissions from Pfizer and Moderna for COVID-19 vaccines that target the KP.2 strain," a spokesperson said on Tuesday. "We are also reviewing a submission from Novavax for a COVID-19 vaccine targeting the [earlier] JN.1 strain."

The regulator said it plans to "complete the review process by early autumn," with doses arriving days after. 

Despite high COVID-19 case counts, some doctors are advising their patients to wait until fall for their next shot. Health Canada is expected to finish its review of several new vaccines by then.

Who should wait to receive an updated vaccine?

Dr. Iris Gorfinkel, a family physician in Toronto, said some of her patients are already asking about a fall vaccine dose.

"The most common question by far and away is, 'Should I get my COVID vaccine now?'" Gorfinkel said. "Right now, because fall is around the corner, I'm recommending that they actually wait. Wait for that better-matched vaccine because chances are it's going to reduce hospitalization." 

The shots aren't expected to perfectly match to circulating subvariants, she added, but they should reduce people landing in hospital.

Bowdish said older adults ask her all the time about COVID vaccinations. "They are really feeling left behind at not having good information."

Federal officials say Canada has "secured sufficient supply of COVID-19 vaccines to meet provincial and territorial requirements for fall and winter 2024 vaccination campaigns."

A fall vaccine could be an option for anyone concerned about maximizing protection over the winter holidays, U.S. officials said.

Who should get a jab right now?

Individuals who are 65 and older, people with underlying conditions, including obesity or heart or lung conditions, should get a fresh dose sooner if they were last vaccinated over six months ago, Gorfinkel advised. That's in line with vaccine recommendations from Canada's national advisory body. 

"Anyone who's at high risk of hospitalization and who is more than six months out from a vaccine is probably better served by getting vaccinated, even if it's an imperfect match right now," Bowdish said. 

The current vaccines available in Canada target XBB.1, an earlier subvariant of Omicron, that was first reported in August 2022, said Ontario health officials.

The new Level 4 lab at the University of Saskatchewan, which will contain the new Canadian Centre for Pandemic Research, is being developed as the federal government is working to improve biosafety and biosecurity measures for high-containment labs — and in the wake of security criticisms at Canada’s existing Level 4 lab in Winnipeg.

Why matching matters

Unlike with the influenza virus that causes flu, there are multiple seasons for COVID-19, including summer peaks. 

The virus that causes COVID-19 is not only changing, but our protection from past infection or immunization also wanes over time, health officials say. 

That's why to get the best protection in season, updated vaccines are recommended.

"The only way you get long COVID is by having COVID," Dr. Peter Marks, vaccine chief for the U.S. Food and Drug Administration, told reporters.

Shehzad Iqbal, country medical director of Moderna Canada, said the updated vaccines will have the same content in Canada and the U.S.

"With the new vaccine formulation coming for the fall, it's much like recharging your batteries and your protection for the upcoming winter season," Iqbal said.