Manitoba pauses use of AstraZeneca COVID-19 vaccine on people under 55

Dr. Joss Reimer, the medical lead for Manitoba's vaccine task force, says despite recent findings that there is no increased risk of blood clots overall, a rare but very serious side effect has been seen, primarily in a small number of young women in Europe.

Officials suspend use in abundance of caution after small number of women in Europe develop blood clots

Dr. Joss Reimer, medical lead of Manitoba's vaccine task Force, said the province is pausing use of the AstraZeneca vaccine in people under the age of 55. (John Woods/The Canadian Press)

Manitoba is pausing the use of the AstraZeneca-Oxford on people under the age of 55 out of an abundance of caution, citing potential safety concerns.

Manitobans aged 55 to 64, who are considered to be at high risk of severe COVID-19 outcomes, will continue to receive the vaccine.

Dr. Joss Reimer, the medical lead for Manitoba's vaccine task force, says despite recent findings that there is no increased risk of blood clots overall, a rare but very serious side effect has been seen, primarily in a small number of young women in Europe.

She says no such issues have been detected in Manitoba. The likelihood of the potential adverse side effects is somewhere in the range of one in 100,000 to one in a million, according to current data. 

"We don't know yet exactly how common this side effect is," she said. "It is still very rare."

The reports of side effects in young women began emerging in Europe about 10 days ago, and the evidence is changing rapidly, she said.

Though the benefits for all ages still probably outweigh any risks, "I'm not comfortable with 'probably,'" Reimer said.

WATCH | Dr. Reimer addresses potential AstraZeneca blood clot link:

Dr. Joss Reimer on rare blood clot side effect of AstraZeneca-Oxford vaccine

2 years ago
Duration 1:02
Dr. Joss Reimer said the province is pausing rollout of the AstraZeneca-Oxford COVID-19 vaccine to Manitobans younger than 55, out of an abundance of caution, in light of a rare side effect seen in Europe.

Less than two hours after Reimer made the announcement, Canada's National Advisory Committee on Immunization (NACI) recommended against use of the AstraZeneca vaccine on people under 55 for safety reasons. 

NACI said the decision was a "precautionary measure" while Health Canada investigates reports of serious blood clots, including cerebral venous sinus thrombosis, from Europe.

Adults 55 and older can still be offered the vaccine, NACI said.

Appointments could be cancelled

The disruption could also lead to the cancellations of vaccine appointments at pharmacies and doctors' offices, she says.

"I am really disappointed to have to tell Manitobans that some of these appointments might be cancelled," she said. "We want to be able to hopefully tell them in the future that we have other vaccine available to them or that we've learned that this vaccine is beneficial and not overly risky."

She says the province will revise its guidelines as more evidence surfaces.

She said it's not yet clear how pausing AstraZeneca's use in people under 55 will impact the province's timeline for COVID-19 vaccination.

WATCH | Unclear how pause will impact vaccination timeline, Dr. Reimer says:

Dr. Joss Reimer on effect of age changes for AstraZeneca on Manitoba's vaccine rollout plan

2 years ago
Duration 0:55
Dr. Joss Reimer, head of Manitoba's vaccine task force, said Monday it's still too early to say for sure what impact a pause on AstraZeneca doses to younger people will be on the province's overall vaccine rollout timeline.

The development is the latest challenge to AstraZeneca's rollout around the world.

Earlier this month, some European countries paused use of the vaccine over concerns of its efficacy, only to resume its use weeks later as new evidence surfaced. Reports of blood clots also emerged in a small number of people in the days after being immunized.

The European Medicines Agency did a review and found no causal link between AstraZeneca and the risk of blood clots.

Data from EMA as of March 18 pegged the risk of serious blood clot events at one in a million, though a more recent study by the Paul-Ehrlich Institut in Germany suggests it's 10-times more common than that, possibly in the range of one in 100,000, according to NACI.

The European drug watchdog did note it couldn't altogether rule out the possibility of a link between the vaccine and rare blood clot types tied to thrombocytopenia, or low levels of blood platelets. The European agency found 18 cases in total of the rare blood clot issue, which is more common in women.

Shot not widely in use in Canada

Health Canada approved use of AstraZeneca for all adults about a month ago, even as NACI advised against using it for anyone over the age of 65, citing a lack of data on outcomes in people older than that.

More recently NACI changed course, following a series of "real-world studies," suggesting it could and should be used for adults over that age. At that point, Manitoba said it would stick with its plan to only give the shot to vulnerable people younger than 65.

The shot hasn't been widely used in Canada, though the country is expected to receive 1.5 million doses of the vaccine from the U.S. — where it has not yet been approved for use — on Tuesday. 

This week, Manitoba expects an additional 54,600 doses of AstraZeneca, 40,950 doses of Pfizer-BioNTech and 28,300 doses of Moderna.

The vast majority of the 248,000 COVID-19 shots already doled out in the province have been Pfizer-BioNTech and Moderna vaccines

The AstraZeneca-Oxford vaccine doesn't have extreme cold storage requirements like the Pfizer-BioNTech and Moderna vaccines, which means it can be administered in pharmacies and doctors' offices. Pfizer and Moderna have primarily been used at Manitoba's five vaccination supersites and on First Nations where proper storage requirements are available.

Eligibility age drops again

Manitoba also lowered the age for vaccine eligibility on Monday by one year. Anyone 64 and older or First Nations people 44 and older can now book appointments at pop-up clinics and supersites.

Reimer also addressed lineups at the RBC Convention Centre vaccination supersite in recent days.

Government officials blamed long line ups at the Winnipeg site on computer glitches.

Reimer apologized Monday, saying wait times there are back in the 10 to 20 minute range.

Manitoba also announced 136 newly detected COVID-19 cases stemming from contagious coronavirus variants in the province on Monday.


Bryce Hoye


Bryce Hoye is a multi-platform Manitoba journalist covering news, science, justice, health, 2SLGBTQ issues and other community stories. He has a background in wildlife biology and occasionally works for CBC's Quirks & Quarks and Front Burner. He won a national Radio Television Digital News Association award for a 2017 feature on the history of the fur trade. He is also Prairie rep for outCBC.

With files from David Cochrane and John Paul Tasker