Why Canada Stopped Using AstraZeneca’s COVID-19 Vaccine for Under 55

Foreign Media/

Details have emerged why Provinces have suspended the use of AstraZeneca’s COVID-19 vaccine for people under age 55 in Canada, after a federal advisory committee recommended against injecting it into younger adults due to reports of “rare” blood clotting events, especially in women in Europe.

After P.E.I., Manitoba and Quebec announced they would pause AstraZeneca vaccinations except for older Canadians, Health Canada hastily called a news conference to say the federal regulator still believes the vaccine is safe and effective in preventing serious illness and death, especially in older Canadians, says a report in Toronto Star.

That group is at higher risk for catching COVID-19, getting very ill — including developing blood clots — and dying, said Dr. Supriya Sharma, Health Canada’s chief medical adviser.

Sharma said regulators will adjust the official authorization to require the company to collect and report more data, and will rely on reports of the vaccine’s ongoing widespread use in the U.K. and other parts of the world to make any further decisions.

For now, the formal authorization for AstraZeneca in Canadians over 18 — which was issued barely a month ago — has not changed. “There really is still a use for the vaccine,” said Sharma.

But experts at the arm’s-length National Advisory Committee on Immunization (NACI) looked at evidence from the U.K. and Europe, where blood clotting cases have emerged.

They involve reports of serious blood clots, including in the brain, with symptoms that mirror a stroke or heart attack occurring four to 20 days after immunization. Symptoms include persistent and severe headaches, blurred vision, shortness of breath, and chest or abdominal pain. The cases have often been associated with a low count of blood platelets — the small cells that help form blood clots to stop bleeding.

The condition can be treated, but NACI noted there is a 40 per cent fatality rate associated with those cases where the clots have been developed.

Until more is known, NACI concluded the provinces should take a precautionary approach. The new guidance also applies to the version of the AstraZeneca vaccine produced by the Serum Institute of India, known as COVISHIELD.

It’s the latest blow to the problem-plagued AstraZeneca rollout.

Developed with Oxford University researchers, the vaccine was once seen as a great hope and potential workhorse because it does not need ultracold freezer storage like vaccines made by Pfizer-BioNTech and Moderna. But its rollout has been plagued by poor communications, mistaken dose measurements in clinical trials, and now this.

NACI chair Dr. Caroline Quach-Thanh likened the vaccine’s debut to “a roller coaster,” but said she hoped that does not contribute to vaccine hesitancy.

Canada is in the midst of distributing 1.5 million doses of Astra-Zeneca’s vaccine made in India, and is set to receive another 1.5 million doses from the U.S. this week.

There have been no reports of this type of blood clotting incident in Canada, said Sharma.

Dr. Shelley Deeks, NACI’s vice-chair and chief of communicable diseases, emergency preparedness and response at Public Health Ontario, said reports of the side effects found in Europe started out as one in a million, but have increased. Germany has reported it in one in 100,000 cases.

There is no clear explanation for the higher incidence among women, said Dr. Isaac Bogoch, an infectious disease specialist who sits on Ontario’s vaccine task force.

Bogoch, said it could be due to the fact that more women have received the AstraZeneca vaccine because they make up a large portion of the health-care workforce, which has priority access for the AstraZeneca vaccination campaign in Europe and the U.K.

Bogoch underlined that it is “a pretty rare type of blood clot, so when you start to see even rare events pop up, you’ve got to take it seriously and you can’t sweep it under the rug.”

For now, he said, it is “reasonable” to suggest that AstraZeneca is still useful for those over 55 and should be withheld for younger people “based on what we know today.”

Ontario’s science advisory table published a paper on the blood clot events Friday, and on Monday the province quickly followed the lead of P.E.I., Manitoba and Quebec.

Ontario has not yet offered the AstraZeneca vaccine to anyone under 60. Chief medical officer Dr. David Williams said the province will follow the NACI recommendation and stressed “we have no concerns with those who have received it so far.”

Premier Doug Ford says he “won’t hesitate to cancel” the distribution of AstraZeneca’s vaccine if it’s going to put anyone in harm’s way. “We just won’t use it — simple as that,” he said.

Ford said he would rather wait for more deliveries of the Pfizer and Moderna vaccines than “roll the dice” on AstraZeneca.

Asked if that means anyone who has had the AstraZeneca vaccine already has taken a chance, Ford replied, “Not at all.”

Some 20 million doses of the AstraZeneca vaccine have been administered worldwide, including to tens of thousands of Ontarians over the age of 60 this month from a shipment of 194,500 received three weeks ago.

The news on AstraZeneca came out just hours after Ontario Health Minister Christine Elliott got her shot on live television in a bid to ease vaccine hesitancy.

While the AstraZeneca vaccines have been available only in 327 pharmacies in Toronto and the Windsor and Kingston areas on a trial basis, the plan is to expand distribution to 700 pharmacies across the province.

About 40 per cent of the 1.5 million doses Canada is set to receive from the United States this week will be allocated to Ontario.

Dr. Howard Njoo, Canada’s deputy chief public health officer, said there is “no cause for concern” for anyone in the 18-55 age group who received a first dose of AstraZeneca if they have had no symptoms. If they are currently in the postvaccination window of four to 20 days, Njoo said they should monitor for symptoms and see a doctor if any develop.

Deeks and Sharma said studies are underway in Europe to look at whether different vaccines can be administered as a second, booster shot, known as “mixed schedule” vaccinations. That data will inform NACI’s future guidance for how to deliver second doses.

0