TORONTO (AP) – A national panel of vaccine experts in Canada on Wednesday recommended that provinces extend the interval between the two doses of a COVID-19 injection to four months to rapidly inoculate more people amid a dose deficiency in Canada.
A number of counties said they would do just that.
Prime Minister Justin Trudeau also expressed optimism that vaccination timelines could be accelerated. And Health Canada, the country’s regulator, said emerging evidence points to high effectiveness for several weeks after the first dose, noting the panel’s recommendation in a tweet. But two top health officials called it an experiment.
The current protocol is a three to four week interval between doses for the Pfizer, Moderna and AstraZeneca vaccines. Johnson & Johnson is a single dose vaccine but has not yet been approved in Canada.
The National Advisory Committee on Immunization said an extension of the dose interval to four months would ensure that as many as 80% of Canadians over the age of 16 would receive a single dose by the end of June, simply with the expected delivery of Pfizer-BioNTech- and Moderna vaccines. .
The second doses would begin to be delivered in July as more shipments come in, the panel said, noting that 55 million doses are expected to be delivered in July, August and September.
In comparison, the federal government previously said 38% of people would receive two doses by the end of June.
“They make a reasonable calculation, I think, in a time of drug shortage,” said Dr. Andrew Morris, professor of infectious diseases at the University of Toronto and the medical director of the Sinai-University Health Network’s Antimicrobial Stewardship Program. . “It’s the right decision in my mind. Let me ask … A couple is getting two vaccines. Do you give two for one, or do you give one per dose? It’s a good idea. “
The addition of the newly approved AstraZeneca vaccine to the country’s stockpile could mean nearly all Canadians would get their first shot in that time frame.
“The effectiveness of the first dose vaccine will be closely monitored and the decision to postpone the second dose will be continuously assessed based on surveillance and efficacy data and post-implementation studies,” the panel wrote.
“Effectiveness against variants of care will also be closely monitored, and recommendations may need to be revised,” he said, adding that there is currently no evidence that a longer interval will affect the emergence of the variants.
The updated guideline applies to all three vaccines currently approved for use in Canada.
The committee’s recommendation came hours after the Atlantic coastal province of Newfoundland and Labrador said it would extend the interval between the first and second dose to four months, and days after health officials in the Pacific coastal province of British Columbia announced they were doing so.
Manitoba and Quebec also said on Wednesday they will delay the second dose. And Ontario’s health minister said it would be Ontario to accelerate vaccine rollout quickly.
Earlier Wednesday, Trudeau said any change in public health guidelines regarding the timing of the two doses could affect the speed of Canada’s vaccine rollout, as well as the approval of more vaccines like Johnson and Johnson.
The Canadian provinces manage health care in the country, so it’s ultimately up to the provinces.
Dr. Brad Wouters, executive vice president of science and research at University Health Network, has doubts about the recommendation. “No one in the world has been between doses for 4 months. These are RNA vaccines that have never been used before. We must use evidence to make decisions. Canada is conducting a population experiment, ”Wouters tweeted.
And Mona Nemer, the federal government’s chief science advisor, also said this week that the plan amounts to a “ population-level experiment ” and that the data provided so far by Moderna and Pfizer-BioNTech is based on an interval of three to four weeks. between doses.
But Dr. Bonnie Henry, British Columbia’s provincial health officer, said the manufacturers have structured their clinical trials to get the vaccines to market as soon as possible, but said research in British Columbia, Quebec, Israel and the United Kingdom has shown that doses are very effective.
Dr. Supriya Sharma, chief medical advisor to Health Canada, the country’s regulator, told the Canadian Broadcasting Corporation that at a time of limited supply, they are starting to feel more comfortable with the idea of waiting for the second dose after seeing real world data versus the strict interpretation of the clinical studies.
“In the real world, we’re starting to see evidence from other countries that have delayed that second dose. ‘Oh, it looks like they still have a really good effectiveness.” We have laboratory studies showing that the immune response is unlikely to decline, ”said Sharma.