After a months-long review, Health Canada regulators on Friday approved the COVID-19 vaccine from Oxford University-AstraZeneca for use in Canada — clearing the way for millions more inoculations in the months ahead.
The department’s regulators have authorized the shot for use in all adults 18 and older, finding the shot had an estimated efficacy rate of 62 per cent.
“Overall, there are no important safety concerns, and the vaccine was well tolerated by participants,” the decision reads.
Canada has secured access to 20 million doses of the AstraZeneca vaccine, which are slated to arrive in the second and third quarters of this year.
Public Services and Procurement Minister Anita Anand has said the government is trying to negotiate a faster delivery of these shots with new, more contagious COVID-19 variants taking hold in Canada.
Some jurisdictions, notably France, have restricted the vaccine to people under the age of 65 despite the World Health Organization’s insistence that the product is safe and effective for all age groups. Health Canada said it has no immediate safety concerns for those 65 and older.
‘Promising evidence’
The regulator said the clinical trial results “were too limited to allow a reliable estimate of vaccine efficacy in individuals 65 years of age and older,” but the department was comfortable approving the shot because of “post-market experience in regions where the vaccine has already been deployed.”
Speaking at a technical briefing Friday, Dr. Supriya Sharma, Health Canada’s chief medical adviser, conceded there was limited clinical trial data about the efficacy of the shot in people over the age of 65, but she said regulators approved it because of “promising evidence from real world use of the vaccine.”
Other countries — notably Australia, the European Union and the United Kingdom — have already authorized AstraZeneca for use in their jurisdictions.
A study of vaccine efficacy in Scotland, where both the AstraZeneca and Pfizer products have been in widespread use for weeks, researchers found the AstraZeneca product reduced the risk of COVID-19 hospital admissions by roughly 94 per cent, 28 to 34 days after the first shot — although, the researchers warned the study sample was quite small.
And, while the AstraZeneca product was found to be less effective than the Pfizer and Moderna shots already approved, Sharma said there could be no doubt that a dose of this shot is more beneficial than no shot at all.
While there are risks associated with any vaccine, Sharma said the benefits of getting of an AstraZeneca shot “outweigh their potential risks.”
Sharma said it will ultimately fall to the National Advisory Committee of Immunization (NACI) to determine which groups should get each type of shot.
She also cautioned Canadians against comparing efficacy rates of the various vaccine products saying, in the areas that matter most — preventing serious illness, reducing hospitalizations and curbing the number of deaths — “all these vaccines are good.”
“If you look across all the clinical trials of the tens of thousands of people who were involved, the number of cases of people who died from COVID-19 that got vaccines was zero,” Sharma said.
“The number of people that were hospitalized because their COVID-19 disease was so severe was zero. The number of people that died because of an adverse event or effect of the vaccine was zero.”
Health Canada is recommending the second dose of the AstraZeneca product be administered four to 12 weeks after the first, but Sharma said there is early evidence that suggests it is best to wait the full 12 weeks to deploy the second shot. “With an increased interval, the efficacy might be much higher.”
In Australia, for example, the product was approved, but regulators there recommended a three-month wait between shots.
Prime Minister Justin Trudeau, members of his cabinet along with Chief Public Health Officer Dr. Theresa Tam and her deputy Dr. Howard Njoo will give an update at 11:30 a.m. ET. CBC News will carry it live.
Regulator still reviewing 2 other vaccine candidates
Health Canada is reviewing two other vaccines: one from Johnson & Johnson and another from Novavax.
The U.S. Food and Drug Administration’s vaccines and related biological products advisory committee will meet today to review the clinical trial data for this vaccine. A final U.S. decision on issuing emergency use authorization (EUA) could follow as early as this weekend.
Canada has ordered 10 million doses from Johnson & Johnson with options for up to 28 million more, if necessary. Most of those shots are expected to arrive by the end of September.
While Health Canada regulators are aiming to make a decision on this product on a timeline similar to the FDA, Sharma said the department is still collecting some data from the manufacturer and a final decision is not expected this weekend.