Canada authorizes Pfizer COVID-19 booster for 16- and 17-year-olds

Canada on Wednesday authorized a single booster shot of Pfizer and partner BioNTech's COVID-19 vaccine for 16- and 17-year-olds.

Regulator Health Canada had cleared an extra dose of the vaccine for people 18 and older in November last year. The booster is meant to be administered six months after the primary two-dose series.

The decision was based on data from two studies of the booster shot among individuals 16 and older. The agency said potential risks of inflammatory heart conditions, myocarditis or pericarditis, have been included in the shot's label.

The cases have been reported after administration of the Pfizer-BioNTech and Moderna's COVID-19 shot, especially among young men. Health Canada had authorized a primary series of Pfizer's shot for those 16 and older in December 2020.

In January, Canada'sNational Advisory Committee on Immunization (NACI) said in an updated guide that adolescents 12 to 17 years old, who are vulnerable to COVID-19 should get booster shots.

That includesthose whohave underlying medical conditions that put them at risk for severe COVID-19 illness,those who live in congregate settings such as shelters, group homesor correctional facilitiesand those who are disproportionately affected by COVID-19 because of their race or marginalization.

The Pfizer-BioNTech vaccine is preferred over Moderna for children and adolescents, NACI said, because "there are currently no data" on the use of Moderna booster doses in that age group.

In the United States, a booster dose of the Pfizer-BioNTech vaccine is cleared for use among children as young as five years.

Myocarditis is rare and treatable: experts

Last year, some researchers said they believethere's a link between mRNA COVID-19 vaccines and a small number of people developingmyocarditis an inflammation of the heart muscle.

Dr. CarolineQuach-Thanh, a pediatric infectious disease specialist and medical microbiologist at CHU Sainte-Justine in Montreal, said myocarditisis "not something that is super common," and in most cases, it goes away after the infection.

In the rare cases that the inflammation affectsthe heart's ability to pump blood, treatments can include anti-inflammatory drugs or steroids.

There's an overwhelming consensus among expertsthat the efficacy of the vaccine outweighs the risk, as getting COVID-19 can pose a serious threat to heart health.