Health Canada has given the green light to an eagerly anticipated fall COVID-19 booster shot in hopes of bolstering the nation’s defence against the virus as the fall season approaches.
The health regulator on Tuesday approved the updated vaccine made by Moderna for all Canadians aged six months and older. Approval for the updated Pfizer and Novavax vaccine under review has not been announced.
The updated mRNA vaccine is tailored to the XBB.1.5 Omicron subvariant that is circulating in the country. It also has additional sequences that target other Omicron variants.
The vaccine is expected to rollout in most provinces and territories at the beginning of October, in alignment with the influenza shot, Canada’s chief public health officer Dr. Theresa Tam said during a briefing on Tuesday.
“This vaccine is anticipated to provide a robust immune response that will be effective against the Omicron XBB.1.5 variant,” Health Canada senior medical advisor Dr. Supriya Sharma said during the Tuesday briefing.
Those who are five years of age and older should receive one dose of the vaccine, regardless of their COVID-19 vaccination history, she said.
Children between six months and four years of age should receive two doses if they have not been previously vaccinated with a COVID-19 vaccine. If they have been previously vaccinated with one or more doses, they should receive a single dose, Sharma added.
The approval comes as new COVID-19 variants — BA.2.86 and EG.5 — circulate the country, raising concerns about the effectiveness of existing vaccines and the need for continued vigilance in public health measures.
Canada has seen an uptick in reported COVID-19 cases over the past few weeks, which Tam credited in part to reduced immunity as the vaccine’s effectiveness wanes over time.
This comes a day after the United States approved updated COVID-19 vaccines. The shots from Moderna and Pfizer are available to most even if they’ve never had a coronavirus vaccination. The Centers for Disease Control and Prevention still must sign off on the vaccinations, which is expected to come Tuesday.
On Sept. 6, Pfizer said its new COVID-19 vaccine elicited a strong antibody response against the highly mutated BA.2.86 variant of the coronavirus in a preclinical study in mice.
Moderna also said clinical trial data in humans showed its updated shot will likely be effective against the variant.
The National Advisory Committee on Immunization (NACI) is still recommending authorized age groups get an updated COVID-19 vaccine dose this fall, six months after their last vaccine dose or infection, Tam said.
Provinces and territories will give additional information on the booster, and Tam said there will be “enough supply of the updated COVID-19 vaccines to support immunization programs across Canada.”
“It is difficult to predict what will happen this fall and winter regarding the co-circulation of influenza, RSV and COVID-19 given that it is still early in the season,” Tam said. “But the good news is, we can get prepared and protect ourselves in case simultaneous surges of respiratory viruses occur.”
Tam stressed the importance of receiving a booster as well as a flu shot this fall, adding it is safe to do so.
“Vaccine protection decreases over time, which means many of us are due for another dose. Receiving a shot of the new formulation will help protect people against the variants circulating currently and expected to circulate through the fall and winter,” Sharma said.
Losing the term 'booster'
Because the COVID-19 vaccine environment has been complex at times, health regulators say they are aiming to streamline the language and the schedules.
In hopes of standardizing the dosing schedule and simplifying terminology, Sharma said moving forward, health regulators may use the term “updated COVID-19 vaccine” instead of “booster.”
“You won’t see the words primary series as much or booster,” she said.
“It’s not quite stabilized yet, but the idea is that we will get to a place where it may be much like the flu vaccine, where people may be on a regular schedule getting an updated vaccine. There is more benefit talking about the latest vaccine or the updated vaccine, rather than going back to years ago when we were talking about the very first two doses or booster.”
— with files from The Associated Press