OTTAWA—Health Canada is demanding that AstraZeneca do a detailed study on the risks and benefits of its COVID-19 vaccine across multiple age groups after getting more reports that patients in Europe developed blood clots following vaccination.
The agency says it has not received any reports of blood clots in Canada to date.
The regulators that review and authorize vaccines are not pulling AstraZeneca’s approval in Canada but say regulatory changes could still be made depending on what the results of this study show.
“Health Canada’s guidance issued to health-care practitioners last week still stands, and provides vaccine recipients with information on the signs and symptoms to monitor for following vaccination,” a statement from Health Canada issued Monday says.
Last week, the department changed its label on the vaccine to warn about the rare risk of blood clots.
Multiple sources confirm to The Canadian Press that the National Advisory Committee on Immunizations will recommend against the vaccine’s use for anyone under the age of 55. They spoke on background because they were not authorized to discuss the move publicly.
NACI provides advice to the provinces on how approved vaccines should be used in the context of the entire number of vaccines available. Provincial governments decide on their own how to use a vaccine, but several announced on Monday plans to stop using it on people under 55, including Prince Edward Island and Quebec.
A briefing with NACI and Health Canada doctors is planned for this afternoon to explain the details to Canadians.
Health Minister Patty Hajdu says Health Canada has been monitoring data very closely following reports of adverse effects in other jurisdictions.
“I can tell you that they’ll be updated messaging from Health Canada and NACI regarding onward use of AstraZeneca and who it might be appropriate for,” she said, at an unrelated news conference Monday morning.
The AstraZeneca vaccine was approved for all people over 18 on Feb. 26, but NACI then said there weren’t enough seniors included in clinical trials to be confident about how the vaccine would perform on people over the age of 65.
Two weeks later, NACI retracted that advice, citing new real-world evidence from the United Kingdom that showed the vaccine was very effective when used on seniors.
This latest recommendation follows reports in Europe that about three dozen patients developed blood clots following immunization with the AstraZeneca vaccine, most of them younger women.
Canada received 500,000 doses of AstraZeneca, made at the Serum Institute of India, but it’s not clear how many have been managed to date. Many provinces prioritized their use for people aged 60 to 64, but some focused on younger groups.
By Mia Rabson