Dr. Supriya Sharma, the agency’s chief medical adviser, said the agency has no plans to change its recommendations, but has updated warnings on the vaccine’s label “so that Canadians can be informed of the side effects.”
“We didn’t find any specific risk factors, such as age or sex, so we are therefore not requiring that the vaccine label be updated to restrict the use of the vaccine at this time,” she said.
After completing a safety review, Health Canada concluded the rare adverse events were “possibly linked to the use of the vaccine,” an assessment Sharma said was “consistent” with other international regulators in Europe and the U.K.
Blood clots or not, she said “the benefits of the AstraZeneca vaccine continue to outweigh the risks of getting COVID-19.”
Sharma added the National Advisory Committee on Immunization (NACI) would be meeting again to discuss the vaccine’s age recommendations. AstraZeneca’s vaccines are currently authorized for adults aged 55 years and older.
The news comes one day after provincial health authorities in Quebec reported a woman had developed a blood clot shortly after receiving an AstraZeneca vaccine dose — the first such report in Canada. The woman, who was not named, is recovering at home.
The AstraZeneca vaccine has been the subject of controversy in recent weeks, following several reports of people getting blood clots within a small timeframe after being immunized.
On Wednesday, Denmark became the first country in the world to completely ditch the vaccine, and a smattering of other European countries have changed their recommendations for the shot.
Sharma said Health Canada first became aware of the “very rare” cases of blood clots with low platelets among vaccine recipients throughout parts of the U.K. and Europe in March.
By the end of March, she said the U.K. had administered more than 20 million doses of the vaccine. Of those, the country’s health regulator found 79 reports of blood clotting.
“This means that based on reports, approximately four in a million, or one in 250,000 people, who received the vaccine reported this side effect,” Sharma said.
The numbers provide a snapshot of how rare the adverse event is.
Blood clotting is a side effect more commonly found with a number of everyday medications, including birth control and hormone replacement therapy.
Put into perspective, the chances of getting blood clots from the AstraZeneca vaccine are “equivalent to the risk of being hit by a car and dying in Toronto in a given year,” Ben Chan, an assistant professor of global health at the University of Toronto, told Global News in a previous interview.
“Yes, these are risks, we should be aware of them, but we need to put them into perspective compared to the daily risks that we have in our lives around us,” he said.
“Just about every medication that we take has some potential for side effects, and all those medications have great advantages to us. They help us keep alive.”
Health Canada approved the two-dose AstraZeneca vaccine in February. The agency has also greenlit the Serum Institute of India’s licensed brand of the vaccine, known as Covishield.
The federal government has secured 20 million doses of AstraZeneca’s shot and 2 million from the Serum Institute. As of April 3, Sharma said Canada had administered more than 484,000 doses of the AstraZeneca and Covishield vaccines throughout the country.