Health Canada has authorized a booster dose of the Pfizer-BioNTech vaccine for children between five and 11 years old, chief public health officer Dr. Theresa Tam said Friday.

Tam said the National Advisory Committee on Immunization recommends children with underlying health conditions should be offered a booster no earlier than six months after their second dose.

All other children in that age group may also be offered a booster, NACI's advice says.

"This booster dose provides a great option to restore protection for this age group, especially for those who are at high risk of severe illness," Tam said. 

Tam said the distinction between NACI's recommendation for high-risk children and all other children — that high-risk kids "should" be offered one and others "may" be offered one — could change as more information is gathered.

"For all other children, the risk of severe outcomes is generally rare," Tam said. "I think giving people the choice and providing parents and kids with the information about the effectiveness of the vaccine and the importance of the booster can help them make this choice."

As children head back to school soon, concerns have been bubbling about COVID-19 transmission at schools. 

Vaccine uptake in that age group is much lower than in all older demographics, with 42 per cent of kids aged five to 11 vaccinated with two doses.

The vaccine rate in every older demographic is higher than 83 per cent.

However, booster uptake among teenagers is also quite low, with fewer than one in five 12 to 17-year-olds receiving a booster eight months after NACI authorized them to get one.

Tam said nationally the latest wave of COVID-19 appears to be either at or past its peak with cases and hospitalizations waning in most regions.

However, Tam said infections are likely to increase during the fall. 

"We want people to get back to normal lives and be able to go to school, go to colleges, get back to work. So under those circumstances, we really do need to layer on the protections," Tam said.

She added that vaccine campaigns should begin to ramp up to get boosters to people ahead of the fall. 

About half of Canadians have received their first booster, while only 11 per cent have received four doses of a COVID-19 vaccine.

This report by The Canadian Press was first published Aug. 19, 2022.