Provinces told to prepare to offer second COVID-19 boosters

OTTAWA — Provinces and territories should quickly get ready to offer fourth doses of COVID-19 vaccines in the coming weeks starting with people over the age of 80 and long-term care residents, the National Advisory Committee on Immunization recommended Tuesday.

NACI strongly recommended a second booster for people between 70 and 79 years of age, and said they may also be offered to people from First Nations, Métis, and Inuit communities.

"Preliminary data indicate that a second booster dose provides additional protection, including against severe disease," the committee reported Tuesday.

In general, a second booster dose should be given six months after the patients got their first booster shots, NACI says, though that optimal timeline will need to be weighed against how rampant COVID-19 is at the local level.

The committee also suggests a recent COVID-19 infection should be factored in, since boosters are best offered at least three months after symptom onset or a positive test.

The latest NACI advice also said a second booster appears to be as safe as previous doses and is well tolerated.

The committee is still studying whether a second booster shot is necessary for younger adults and adolescents.

Second boosters, or fourth doses, are not approved by Health Canada but can still be offered on an "off-label" basis.

The recommendations were made in light of the potential for waning effectiveness of booster doses against severe disease. Several provinces have already offered a second booster to higher-risk groups with plans to expand eligibility soon.

Approximately 90 per cent of Canadians over the age of 18 are considered fully vaccinated in Canada as of March 27, which for the majority of Canadians means two doses of the vaccines approved by Health Canada.

NACI recommended a third shot for adults in December but people have been slower to get their boosters than they were to get the first and second doses.

Just 57 per cent of people over 18 years old have received a booster dose, according to data from the Public Health Agency of Canada.

Older people who are at higher risk of severe outcomes related to the virus have been more amenable to the idea of extra jabs, with more than 84 per cent of seniors over 70 getting a third dose and 68 per cent of those aged 50 to 69.

The Council of Chief Medical Officers of Health urged Canadians to follow advice on boosters.

"Staying up-to-date with COVID-19 vaccines provides you with strong protection against severe illness and hospitalization and helps to reduce the overall impact and severity at the population level," the council said in a statement.

The new NACI recommendations come at the same time as concerning indications that Canada may already be heading into another pandemic wave. The medical officers of health said vaccines are the best line of defence against a surge in hospitalizations.

"Vaccination remains the most important tool to protect ourselves and our communities against the impacts of future waves of COVID-19," they said.

This report by The Canadian Press was first published April 5, 2022.