The expert panel that advises Ottawa on which people to prioritize for vaccination is reconsidering its position that the COVID-19 vaccine made by AstraZeneca should not be given to Canadians who are 65 and over.
Meanwhile, European countries including Austria, Denmark and Italy have suspended administering the vaccine, either from specific batches or entirely, while investigating reports of blood clots in individuals who received the shot.
Caroline Quach-Thanh, who chairs the National Advisory Committee on Immunization, told The Globe and Mail on Thursday that committee members had met this week to review new data about the effectiveness of the vaccine in seniors. She said an updated statement on its use would be issued, “in a few days.”
Dropping age restrictions on the vaccine would put the committee in line with several countries that have already done so, as well as Health Canada regulators who from the start authorized the vaccine for adults 18 and over in February. Provinces are not bound by the committee’s recommendations and Quebec has already opted to make the AstraZeneca vaccine available to seniors.
Dr. Quach-Thanh noted that the advisory committee’s initial statement on the vaccine was made based on data available before March 1, which the committee deemed insufficient to provide a recommendation for those in the older age group. Since then, she said, two more British studies have appeared that provide additional data on seniors who have received the vaccine.
European officials say they are now investigating the blood-clotting incidents. Experts caution that while potential adverse reactions should be thoroughly checked, it is inevitable that unrelated health problems and death will occur after individuals have been vaccinated at a rate that is comparable to the general population.
The vaccine has already been administered to tens of millions of people worldwide.
“Any side effect that’s common should already be obvious,” said Matthew Muller, an infectious-disease physician with the Unity Health group in Toronto, who is part of a project to monitor COVID-19 vaccine safety in Canada. “We should be open-minded, but I think the appropriate thing here is to gather more information.”
The AstraZeneca vaccine has posed a conundrum for some Canadians because of its lower average efficacy. That was determined to be 62 per cent in clinical trials – a clear contrast with vaccines made by Pfizer-BioNTech and Moderna, which both scored better than 90 per cent. However, the vaccines are much closer in performance when considering their ability to prevent serious disease and death rather than all symptoms regardless of how mild.
Also important for those awaiting vaccination is the growing threat of infection posed by more transmissible variants of the coronavirus. The scarcity of doses of other authorized vaccines in Canada means that the AstraZeneca shot could play a crucial role in preventing a third wave of infections.
“Vaccines save lives,” said Cole Davidson, a spokesperson for federal Health Minister Patty Hajdu. “All of the vaccines authorized by Health Canada are safe and effective … and we encourage all Canadians to get vaccinated when their turn comes.”
On Thursday, B.C. Provincial Health Officer Bonnie Henry said she was on a call with Health Canada about the issues around the AstraZeneca vaccine, including the safety questions coming out of Europe.
“We have not seen any of those types of issues here in B.C., although we just started to use the AstraZeneca vaccine,” she told reporters at a briefing.
In Italy, national and Sicilian media have reported the deaths of two Sicilian men after they received the AstraZeneca vaccine. According to a report from Reuters, Italian health authorities ordered the withdrawal of a batch of the vaccine, designated ABV2856, after the deaths, but it was a precautionary measure and no direct link had been established. Local media reported that a 43-year-old navy officer died of a heart attack the day after his shot and a 50-year-old policeman died some 12 days after being diagnosed with deep vein thrombosis after his jab.
The European Medicines Agency (EMA), which is conducting the investigation into the product, said in a statement on Thursday, “There is currently no indication that vaccination has caused these conditions, which are not listed as side effects with this vaccine.”
The quality of a different batch used in Austria, where another death was reported, will also be inspected for possible defects.
That batch of one million doses, known as ABV5300, was used in 16 other countries in the European Union, including Spain, Sweden and the Netherlands.
In a statement issued Thursday evening, Health Canada said none of the identified batches under investigation have been shipped to Canada.
Austria intends to suspend use of the vaccine for 14 days while the investigation takes place. By Thursday, seven European countries, including Iceland, Estonia and Luxembourg, had halted the use of the ABV5300 batch. The Spanish Health Ministry said it would continue to administer doses from the batch because it was unaware of any related cases of blood clots.
In an interview, Pierre Morgon of MRGN Advisors, a Swiss-based biotech and vaccine consultancy, said: “This is a reminder that the safety database of a novel medication isn’t comprehensive until there’s a very large number of people having used the medication, representing all, or almost all, medical situations and conditions.”
Typically, vaccines and other medications are developed through clinical trials with inclusion and exclusion criteria. Any adverse effects among people with medical conditions excluded from the trials would not be known until after a product was approved and made available to the public.
AstraZeneca said patient safety was its “highest priority” and that the vaccine “has been extensively studied in Phase 3 clinical trials, and peer-reviewed data confirms the vaccine has been generally well tolerated.”
With a report from Xiao Xu
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