TORONTO (AP) – A national panel of Canadian vaccine experts on Wednesday recommended that provinces extend the interval between two doses of a COVID-19 vaccine to four months to quickly inoculate more people amid dose shortages in the Canada.
Several provinces said they would do just that.
Prime Minister Justin Trudeau also expressed optimism that vaccination schedules could be accelerated. And Health Canada, the country’s regulator, said the evidence suggests high efficacy for several weeks after the first dose and noted the panel’s recommendation in a tweet. But two senior health officials called it an experience.
The current protocol is an interval of three to four weeks between doses of the Pfizer, Moderna and AstraZeneca vaccines. Johnson & Johnson is a single dose vaccine, but has not yet been approved in Canada.
The National Immunization Advisory Committee said that extending the dose range to four months would allow up to 80% of Canadians over 16 to receive a single dose by the end of June simply with the expected supply of Pfizer-BioNTech and Moderna vaccines.
The second doses will begin to be administered in July, as more shipments arrive, the panel said, noting that 55 million doses should be delivered in July, August and September.
In comparison, the federal government previously said that 38% of people would receive two doses by the end of June.
“They are doing, I think, a reasonable calculation in a time of drug shortage,” said Dr. Andrew Morris, professor of infectious diseases at the University of Toronto and medical director of the Antimicrobial Administration Program at the Sinai University Health Network . “It is the right decision in my mind. Let me ask … A couple gets two vaccinations. Do you give two to one, or give each one a dose? It’s a no-brainer. “
The addition of the newly approved AstraZeneca vaccine to the country’s supply could mean that almost all Canadians would have their first injection in that period of time.
“The effectiveness of the first dose vaccine will be closely monitored and the decision to postpone the second dose will be continuously evaluated based on surveillance and efficacy data and post-implementation study designs,” wrote the panel.
“The effectiveness against the worrying variants will also be closely monitored, and the 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 guidance applies to all three vaccines currently approved for use in Canada.
The committee’s recommendation came hours after the Atlantic coast province of Newfoundland and Labrador said it would extend the interval between the first and second doses to four months, and days after British Columbia provincial health officials announced they were taking this.
Manitoba and Quebec also said on Wednesday that they would postpone second doses. And Ontario’s health minister said it would be Ontario to speed up the vaccine’s launch.
Earlier on Wednesday, Trudeau said that any change in public health guidance regarding the timing of the two doses could affect the speed of vaccine launch in Canada, as well as the approval of more vaccines like Johnson and Johnson.
Canada’s provinces administer health care in the country, so it ultimately depends on the provinces.
Dr. Brad Wouters, executive vice president of science and research at the University Health Network, cast doubt on the recommendation. “Nobody in the world was 4 months between doses. These are RNA vaccines that have never been used before. We must use evidence to make decisions. Canada conducting a population experiment ”, tweeted Wouters.
And Mona Nemer, a scientific adviser to the federal government, 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 are based on a range of three to four weeks between doses.
But Dr Bonnie Henry, British Columbia’s provincial health officer, said manufacturers have structured their clinical trials in this way to get vaccines to market as quickly as possible, but said research in British Columbia, Quebec, Israel and the UK United have shown this first the doses are highly effective.
Dr. Supriya Sharma, chief medical consultant for Health Canada, the country’s regulator, told Canadian Broadcasting Corporation in a limited supply moment that they are beginning to feel more comfortable with the idea of waiting for the second dose after seeing real-world data versus strict interpretation of clinical trials.
“In the real world, we are starting to see evidence from other countries that have postponed the second dose ‘Oh, it looks like they are still very effective.’ We have laboratory studies that show that the immune response is unlikely to decrease, ”said Sharma.