Canada will recommend AstraZeneca-Oxford vaccine for those over 65, documents show

mRNA vaccines like Moderna and Pfizer-BioNTech will still be 'prioritized' for seniors: documents

Cbc.ca
March 16, 2021
Adam Miller

Canada will change its guidelines on the AstraZeneca-Oxford COVID-19 vaccine and recommend it be given to those over age 65, according to documents obtained by CBC News and sources with direct knowledge of the guidelines.

The National Advisory Committee on Immunization (NACI) previously recommended Canadians over 65 not receive an AstraZeneca-Oxford shot earlier this month, despite emerging evidence from around the world demonstrating its ability to prevent severe COVID-19 in older adults.

But the NACI recommendations were based largely on AstraZeneca-Oxford's clinical trial data and didn't examine real-world evidence past Dec. 7 -- months before the effectiveness of the vaccine was fully realized in other countries for older age groups.

Those recommendations led provinces to reorganize their vaccination plans for seniors and meant those aged 60-64 could receive the shots ahead of older age groups, who are at greater risk of hospitalization and death from COVID-19.

Sources with firsthand knowledge of the new recommendations confirmed to CBC News that NACI plans to update its guidelines on the vaccine Tuesday.

Documents obtained by CBC News -- marked "final" and dated Tuesday, but which may be subject to change -- show the decision is based on emerging real-world data from other countries. The recommendations also state that mRNA vaccines, such as those from Pfizer-BioNTech and Moderna, will still be "prioritized" for older age groups.

"Following this careful review, NACI decided to expand recommendations for the use of the AstraZeneca-Oxford vaccine to include those 65 years of age and over," the documents read.

The documents state real-world data of vaccine effectiveness -- for those over 65 who received one dose of AstraZeneca's -- saw a "reduction in the risk of symptomatic disease and hospitalization" that appeared to reach a "comparable level" to those aged 18 to 64.

CBC News reached out to representatives from NACI, Health Canada and the Public Health Agency of Canada for comment but did not receive a response by publication time.

No evidence
Other countries such as France and Germany initially advised those 65 and older not to receive the shot, but overturned their decisions earlier this month after new evidence showed the vaccine significantly reduced hospitalizations in that age group.

But Germany followed other European countries like Denmark and Norway on Monday and suspended the use of the AstraZeneca-Oxford shot over reports of blood clotting in some recipients of the vaccine. Italy and France did the same.

AstraZeneca-Oxford said Sunday a "careful review" of all available safety data for more than 17 million people vaccinated in the European Union and the U.K. showed "no evidence of an increased risk" of blood clots.

It's unclear if NACI's guidelines for the vaccine will change further in light of the blood clotting reports, but the documents make no mention of them and there is no evidence to suggest Canada will follow suit in suspending the use of the shot.

Prime Minister Justin Trudeau said Monday the AstraZeneca-Oxford vaccine is safe and Canadians should have no concerns about receiving it.

Already hesitant
It's unclear how the change in recommendations will affect provincial and territorial vaccine rollout plans, given that those aged 60-64 have already started receiving shots and continue to be booked for appointments.

Quebec is the only province so far to ignore the national recommendations. Officials there said last week they would administer the AstraZeneca-Oxford vaccine to seniors.

Dr. Zain Chagla, an infectious diseases physician and medical director of infection control at St. Joseph's Healthcare Hamilton, said the vaccine has already raised concerns from the public because the clinical trials underestimated its effectiveness, did not enroll enough people over 65 and lacked key data because few participants actually got infected with COVID-19.

"People are already hesitant around this vaccine from that," he said. "And even if you do get better data to support its use you now still have to fight against these three different streams of negativity towards this vaccine."

Dr. Nathan Stall, a geriatrician at Mount Sinai Hospital in Toronto, said issues with data from Scotland, regarding the effectiveness of the vaccine in older age groups, may have factored into NACI's initial decision.

"Overall, what has happened with the AstraZeneca vaccine has been very, very unfortunate from almost the get-go," said Stall, who is a member of NACI but does not speak on behalf of the committee. "So many things, unfortunately, went wrong along the way."

Stall said the reported blood clotting also "reared its ugly head" at an extremely unfortunate time.

"Then of course, people see a product that I think they perceive as inferior," he said. "Secondly, [the initial shipment] expires on April 2, so people feel like this is sort of like this second rate product that's imminently expiring that the government is trying to get rid of."

Stall said all of those factors combined have led to a "very, very understandable but unfortunate perception" that AstraZeneca-Oxford's is somehow a "bad vaccine" -- which simply isn't true.

"I do believe that probably when all is said and done, that the AstraZeneca vaccine is going to show similar real world efficacy in terms of preventing those outcomes we care most about, the hospitalizations and deaths, very comparably to the mRNA vaccines," he said.

Matthew Miller, an associate professor of infectious diseases and immunology at McMaster University in Hamilton, said the emergence of real-world data allows officials to continually assess how effective the vaccine is globally.

"That data is now very strongly suggesting that the vaccine is working in those older individuals, and is particularly good at preventing severe infection and hospitalization, which are ultimately the outcomes that are most important," said Miller, who also works with NACI.

"What we don't want to have happen is these individuals, especially those who belong to vulnerable demographics, becoming seriously ill, hospitalized and dying. Those are the things that stretch ICU capacity and so those are the outcomes of greatest concern."

Chagla says clear, transparent communication from politicians and public health officials is needed in order to explain to Canadians why the change was made.

"It wasn't the fact that it was ineffective, it was the fact that there just wasn't data -- but there is now," he said.

"There is going to be a stigma done by this but at least if people have the right information to make an educated decision and feel like their public health officials are being open and transparent with them, it at least encourages people to make the decision that they need to."