An earlier version of this article reported incorrectly, based on information provided by a Pfizer representative, that Canada was the first country to authorize the Pfizer-BioNTech vaccine for use in children ages 12 to 15. Pfizer said subsequently that Canada was the second country to authorize such use after Algeria, which did so in April. The article has been corrected.
Supriya Sharma, chief medical adviser for Health Canada, said the agency reviewed the data from a Pfizer study in the United States involving more than 2,200 adolescents age 12 to 15. Half received the two-dose regimen administered to adults; the others were given a placebo.
The study found the vaccine was 100 percent effective in preventing infection among participants who received two doses, Sharma said during a news conference in Ottawa. There were 18 cases of covid-19 among those who received a placebo. The participants given the vaccine produced strong antibody responses, similar to those observed in young adults age 16 to 25.
Some participants reported temporary and mild side effects, including sore arms, fever and chills.
The announcement was welcome news for the many parents and children whose lives have been upended by the pandemic.
Several provinces and territories began the school year with in-person learning — officials said it was key to reopening the economy, and many pediatricians said that with the appropriate public health measures in place, the risks of keeping children home outweighed those of sending them to class.
But as cases in many provinces have surged, schools have on multiple occasions reverted to online learning, severing children from their social networks, keeping them out of extracurricular activities and putting stress on parents.
People younger than 19 account for about 20 percent of Canada’s coronavirus cases, Sharma said. They have been far less likely to experience severe illness. Nine of Canada’s more than 24,400 deaths have been in those younger than 19, according to the Public Health Agency of Canada.
“While younger people are less likely to experience serious cases of covid-19, having access to a safe and effective vaccine will help control the disease’s spread to their families and friends, some of whom may be at a higher risk of complications,” Sharma said. “It will also support the return to a more normal life for our children, who have had such a hard time over the past year.”
While Canadians are “starting to see the light at the end of the tunnel,” she said, they should continue to wear face masks, observe social distancing and wash hands until a majority of the population is vaccinated. Nearly 35 percent of the population has received at least one dose.
Several provinces are battling a punishing third wave that has triggered new restrictions on businesses and social life. Alberta has the highest rate of coronavirus cases per capita of any Canadian province or U.S. state.
Canada cleared the Pfizer vaccine for use among those 16 and older in December, ahead of the United States and Europe. But its vaccination drive got off to a slow start, leaving many Canadians frustrated as they watched inoculations increase across the border in the United States.
With little capacity to manufacture vaccines at home, Canada has been reliant on deliveries from abroad. The government signed advance purchase agreements with several drugmakers for access to many more potential doses than it needs for its population of 38 million. But supply chain problems, manufacturing delays and backloaded delivery schedules have meant that doses have at times been slow to arrive. Chaotic rollouts in some provinces and seemingly conflicting messaging on vaccines among politicians, public health officials and a panel of scientists that provides advice on immunizations have not helped.
Canada has administered fewer than 38 doses per 100 people, according to Oxford University’s Our World in Data. That’s less than half the rate in the United States.
The pace of vaccinations has quickened considerably in recent weeks; the country now ranks third among the Group of Seven countries in the percentage of people who have received at least one dose. But less than 4 percent of Canadians have been fully vaccinated, compared with nearly one-third in the United States. That’s in part because Canada, with limited supplies, is stretching the interval between doses to up to four months to get a first shot into as many arms as possible.
Officials here say they’ll be able to offer a vaccine to everyone who wants one by the end of September.
Albert Bourla, Pfizer’s chairman and chief executive, told investors in a conference call Tuesday that he expected the Food and Drug Administration to authorize the vaccine for use among 12- to 15-year-olds in the United States “shortly.”
Health Canada said it will expedite reviews of other vaccine manufacturers seeking authorization for children and adolescents.
Berger reported from Jerusalem.