TORONTO (AP) – Canada on Monday suspended use of the Oxford-AstraZeneca coronavirus vaccine for people under 55 over fears it could be linked to rare blood clots.
The National Advisory Committee on Immunization had recommended the break for safety reasons and the Canadian provinces, which administer health in the country, announced the suspension on Monday.
“There is considerable uncertainty about the benefits of providing AstraZeneca Covid-19 vaccines to adults under the age of 55 given the potential risks,” said Dr. Shelley Deeks, vice chair of the National Advisory Committee on Immunization.
Deeks said the updated recommendations come from new data from Europe that suggests the risk of blood clots is now potentially as high as one in 100,000, far higher than the risk of one in a million. it was believed before.
She said most of the patients in Europe who developed a rare blood clot after vaccination with AstraZeneca were women under the age of 55, and the death rate among those who develop clots can be as high as 40%.
Dr Joss Reimer, of the Manitoba Vaccine Implementation Working Group, said that despite the finding that there was no increased overall risk of AstraZeneca-related blood clots in Europe , a rare but very serious side effect has been observed mainly in young women in Europe.
Reimer said the rare type of blood clot usually occurs between four and 20 days after the vaccine, and symptoms may reflect a stroke or heart attack.
“While we still believe that the benefits for all ages outweigh the risks, I’m probably uncomfortable. I want to see more data coming out of Europe so that I know exactly what this risk-benefit analysis is, ”Reimer said.
The AstraZeneca shot, which has been licensed in more than 70 countries, is a mainstay of a UN-backed project known as COVAX that aims to deliver COVID-19 vaccines to poorer countries. It has also become a key tool in European countries’ efforts to boost their slow vaccine launches. This makes doubts about the plans particularly worrying.
“This vaccine has had all its ups and downs. It feels like a roller coaster ride, ”said Dr. Caroline Quach-Thanh, chair of the National Advisory Committee on Immunization, when asked if the latest news would lead to increased hesitation about vaccines.
Health Canada said it had not received any reports of blood clots in Canada, and the department’s chief medical adviser, Dr. Supriya Sharma, said she still believed the benefits of the vaccine outweighed the benefits. risks.
Last week, the department changed its label on the vaccine to warn of the rare risk of blood clots.
Only those aged 60 and over received AstraZeneca in Ontario, the most populous province in Canada.
“We have no problem with those who have received it so far,” said Dr. David Williams, Chief Medical Officer of Ontario.
Several European countries that had suspended use of the vaccine over fears that it could cause blood clots resumed administering it after the European medicines regulator said the vaccine was safe.
The vaccine is widely used in Britain, mainland Europe and other countries, but its rollout has been marred by inconsistent study reports on its effectiveness, and then more recently by fear of clots that have led to some countries to temporarily suspend inoculations.
Canada is expected to receive 1.5 million doses of AstraZeneca from the United States this week.
“The message was blunt overall. I’m afraid it’s a toast. It shouldn’t be, ”said Dr. Andrew Morris, professor of infectious diseases at the University of Toronto and medical director of the antimicrobial stewardship program at the Sinai-University Health Network.
Morris believes those at high risk of poor COVID-19 results and who are over 55 should be given AstraZeneca if other vaccines are not available to them, especially during a third wave of coronavirus infections.
Canadian regulators have approved Pfizer, Moderna, AstraZeneca and Johnson & Johnson vaccines. Canada has bet more on Pfizer and Moderna, ordering up to 76 million doses of Pfizer and up to 44 million Moderna, against up to 20 million of AstraZeneca. It is not known when Canada will receive its first delivery from Johnson & Johnson.
Canada has been slow to vaccinate its people because it lacks the capacity to manufacture the vaccine and has had to rely on the global supply chain for life-saving vaccines, like many other countries.
With no domestic supply, Prime Minister Justin Trudeau’s government has gambled on seven different vaccines made elsewhere and made advance purchase agreements – enough to get 10 doses for each of Canada’s 38 million people. While their acquisition proved difficult, deliveries accelerated this month. Canada expects to have more than 36.5 million doses by July and officials hope to deliver at least one dose to all adults who want one by the end of June.
The National Advisory Committee on Immunization had previously recommended a four-month delay between doses after data from the UK and Quebec showed a good level of protection offered by the first injection. The UK has instituted a similar time limit.