Canada is suspending the use of the Oxford-AstraZeneca COVID-19 vaccine for people under the age of 55 following concerns it may be linked to rare blood clots.
The National Advisory Committee on Immunisation recommended a pause on AstraZeneca COVID-19 vaccinations for people under 55 for safety reasons and the Canadian provinces, which administer health in the country, announced the suspensions on Monday.
"There is substantial uncertainty about the benefit of providing AstraZeneca COVID-19 vaccines to adults under 55 given the potential risks," Dr. Shelley Deeks, Vice Chair of the National Advisory Committee on Immunisation.
Dr. Joss Reimer of Manitoba's Vaccine Implementation Task Force said despite the finding that there was no increase risk of blood clots overall related to AstraZeneca in Europe, a rare but very serious side effect has been seen primarily in young women in Europe.
"So out of abundance of caution, Manitoba will be recommending that these vaccines only be used in people who are 55 or older at this time. I do want to say this is a pause while we wait for more information to better understand what we are seeing in Europe," Reimer said.
Reimer said the increase in the rare type of blood clot happens affects somewhere around one in 100,000 or one in a million people who receive AstraZeneca. She said it typically happens between four and 20 days after getting the shot and the symptoms can mirror a stroke or a heart attack.
Reimer said they have not seen any of these cases in Canada.
"While we still believe the benefits for all ages outweigh the risks I'm not comfortable with probably. I want to see more data coming out of Europe so I know exactly what this risk benefit analysis is," Reimer said.
The AstraZeneca shot, which has been authorised in more than 70 countries, is a pillar of a UN-backed project known as COVAX that aims to get COVID-19 vaccines to poorer countries. It has also become a key tool in European countries' efforts to boost their sluggish vaccine rollouts. That makes doubts about the shots especially worrying.
"This vaccine has had all the ups and downs. It looks like a roller coaster," said Dr. Caroline Quach-Thanh, the chair of the National Advisory Committee on Immunisation, when asked if the latest news will lead to further vaccine hesitancy.
Health Canada, the country's regulator, called the pause a precautionary measure.
Several European countries that had suspended using the vaccine over concerns it could cause blood clots have resumed administering it after the EU's drug regulator said the vaccine was safe.
The vaccine is used widely in Britain, across the European continent and in other countries, but its rollout was troubled by inconsistent study reports about its effectiveness, and then more recently the scare about clots that had some countries temporarily pausing inoculations.
Canada is expected to receive 1.5 million doses of AstraZeneca from the US this week.