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National health committee endorses COVID-19 booster shots for Canadians 50 and older

The National Advisory Committee on Immunization adds the effectiveness of the booster against the new Omicron variant is still being studied, but since Delta accounts for 98% of all cases in Canada, getting the booster now is advised

Canada's National Advisory Committee on Immunization (NACI), the group of science experts that studies the COVID-19 vaccines, said Friday the move to provide third-dose booster shots for people 50 and older is the right course of action at this time. 

While it is not known if the booster will be effective against the new Omicron variant, the experts said the safest bet is for older residents to get the shot now. The statement was made during an online technical briefing held for the media. 

It was announced Thursday that Ontario residents aged 50 and older will be able to begin making appointments for their third-dose booster as of Dec. 13. 

When asked why NACI isn't pushing to have the extra vaccine dose given to people younger than 50, Canada’s chief public health officer, Dr. Theresa Tam, said it was partly logistics and partly because younger people don't need the booster as urgently as older residents. 

Tam said most of the older people in Canada were immunized at an earlier point in time during 2020 than the younger residents.

"The recommendation is that the booster should be offered six months or more after the completion of a primary series (of vaccines)," said Tam.

"The data we have at the moment shows that the vaccines are holding up pretty good against severe outcomes. We are most concerned about severe outcomes in those who are elderly or have other higher-risk conditions." 

She added that data is also showing there was "a waning of the vaccine effectiveness over time” against asymptomatic infections and symptoms. The briefing was also told that in general, Canadians over 50 years do have increased rates of underlying medical conditions. 

The NACI group was also challenged on whether Canadians should wait for an updated version of a booster vaccine, one that is potentially more effective against the new Omicron variant of the coronavirus. Tam said it would not be effective to do that.

"So at this current moment the Delta variant is the most dominant variant. It's like 99.8 per cent of what we have in Canada. And so we have to mitigate the risk of this present threat," Tam told the briefing.

At the same time, Tam said science still does not have a full understanding of how the Omicron variant will respond to the third-dose booster. She said it is best to play it safe and get a booster shot now. 

"And so I think the extent of the protection against Omicron from the primary series and booster dose remains to be seen. And we're going to learn a lot about this in the days to come. But nevertheless, it is still prudent to maximize the possibility of protection from vaccines by first of all, offering the vaccine to anyone who hasn't had the primary series, but then offering the boosters as we've just laid out," said Tam.

She added that "it will take months" before a new vaccine is developed that is "Omicron specific."

Len Gillis is a Local Journalism Initiative reporter at He covers health care in Northern Ontario.


Len Gillis, local journalism initiative reporter

About the Author: Len Gillis, local journalism initiative reporter

Len Gillis is a Local Journalism Initiative reporter at covering health care in northeastern Ontario and the COVID-19 pandemic.
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