“From what is known at this time, there is substantial uncertainty about the benefit of providing AstraZeneca COVID-19 vaccine to adults under 55 years of age,” the council said in a written recommendation.
Older people face a greater risk of hospitalization and death from COVID-19, and the complication seems to be more rare in that age group, NACI said, so they can be offered the vaccine “with informed consent.”
In response to NACI’s guidance, Canada’s Council of Chief Medical Officers of Health, which includes provincial and federal representatives, said it would pause the vaccine for those under 55.
The council said it considered the fact that Canada had other vaccines available when making the decision. Most of Canada’s supply has so far come from Pfizer Inc and Moderna Inc.
Some 11.8% of Canada’s population has received at least one dose of a COVID-19 vaccine, according to Reuters’ vaccine tracker.
Separately, Health Canada, the country’s drug regulator, said it would add terms and conditions to the AstraZeneca vaccine’s authorizations, including “a requirement that the manufacturers conduct a detailed assessment of the benefits and risks of the vaccine by age and sex in the Canadian context.”
Health Canada said it had been in talks with AstraZeneca, and once it has the requested information, it “will determine if additional regulatory actions are necessary.”