Canada approves Pfizer-BioNTech boosters for all adults.

Canada’s health agency authorized booster shots of the Pfizer-BioNTech vaccine nationwide on Tuesday, broadening eligibility to anyone over the age of 18, regardless of what vaccine they received initially.

Health Canada, the federal department responsible for approving drugs, and the National Advisory Committee on Immunization had previously updated vaccine guidelines in September to recommend booster shots for seniors living in congregate settings and for people with compromised immune systems.

The new guidelines cite early evidence from two studies in Israel, including an Oct. 7 article published in The New England Journal of Medicine, which found that rates of “severe illness were substantially lower” for those who received a third Pfizer-BioNTech dose. Israel approved those booster shots on July 30.

In Canada, where the administration of health care falls under provincial control, some provinces had already begun to offer booster doses based on the interim federal guidelines. On Oct. 29, eligibility was expanded to frontline health workers, adults over 70, First Nations communities, and people who received two doses of AstraZeneca or one dose of the Johnson & Johnson vaccine.

Provinces including Ontario, British Columbia and Saskatchewan have already begun administering booster shots to these populations, or to people traveling to countries that require certain vaccines.

The Health Canada announcement on Tuesday standardized eligibility criteria across the country. The agency recommended that adults receive the Pfizer booster at least six months after their last dose.

Pfizer is also seeking regulatory approval for its vaccine to be administered to children aged 5 to 11, Prime Minister Justin Trudeau announced last month, with the country slated to receive 2.9 million pediatric doses when the authorization is granted.

As of Oct. 30, close to 74 percent of the country’s population was fully vaccinated, according to federal data.