Alberta joins other provinces in halting use of AstraZeneca shot for people under 55

·3 min read

EDMONTON — Alberta's top doctor says the roughly 900 people in the province under 55 who have received a first dose of Oxford-AstraZeneca's COVID-19 vaccine are at low risk of complications and there's ample time to figure out what should be done for their second shot.

Alberta on Monday joined other provinces in pausing use of the vaccine in that age group. A national immunization advisory committee recommended the precaution, because of uncertainty around the potential risk of rare blood clots in younger recipients.

"I know this sort of news may cause some concern for Albertans and that is understandable," said chief medical officer Dr. Deena Hinshaw.

"However, I want to assure you that this temporary pause is the result of our robust safety monitoring working the way that it should."

The Alberta government has said that all adults who want a shot should be able to get one by the end of June. Hinshaw said that target may still be achievable even without the AstraZeneca vaccine as shipments of Pfizer-BioNTech and Moderna doses ramp up.

She said the blood clots are a rare complication. Reported ranges put them between one in 25,000 in Norway and one in one million in the United Kingdom, so the chances of any of the 900 Albertans under 55 who have received the shot is vanishingly small.

The province has less than 200 doses left from its initial AstraZeneca supply of 58,500, and those have expiry dates beyond May, Hinshaw added.

Alberta began offering the AstraZeneca shot earlier this month to anyone born between 1957 and 1961 and First Nations, Metis and Inuit people born between 1976 and 1972. It was initially not recommended for those older than 65 amid concerns about its efficacy in older people that have since been dispelled.

Hinshaw said AstraZeneca has been shown to prevent severe illness from COVID-19, which itself comes with a significant risk of blood clots and other complications.

"In other words, the benefits of getting the vaccine far outweigh the small potential risks in groups more likely to have severe outcomes from COVID-19 infection, such as those age 55 and older."

Hinshaw said with a 16-week gap between AstraZeneca shots believed to be effective, there's time to gather more evidence around the rare blood clots.

She said health officials will also be watching clinical trials in the United Kingdom that are looking at the effectiveness of mixing and matching different vaccines for the first and second doses. That means someone who initially got an AstraZeneca shot could potentially boost immunity with a Pfizer followup jab.

The province also said Monday it is pressing ahead with the next phase of its vaccine rollout covering nearly one million Albertans with underlying health conditions. Those born in 1963 and earlier will be able to start booking appointments at pharmacies starting Tuesday. Alberta Health Services sites are to open up spots a week later for anyone born in 1959.

New birth years will be added as more supply becomes available.

Alberta has administered a total of 608,000 vaccine doses to date.

It reported 545 new cases of COVID-19 on Monday. There were 288 people in hospital, 64 of them in intensive care.

More transmissible virus variants now make up 27 per cent of active cases. There were no new deaths reported, leaving that total at 1,983.

— By Lauren Krugel in Calgary

This report by The Canadian Press was first published March 29, 2021

The Canadian Press