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 shot to four months to vaccinate more people quickly amid a shortage of doses in Canada.
A number of provinces have said they will do just that.
Prime Minister Justin Trudeau also expressed optimism that the timelines for vaccination could be accelerated. And Health Canada, the country’s regulator, said emerging evidence points to high effectiveness for several weeks after the first dose and noted the panel’s recommendation in a tweet. But two top health officials call it an experiment.
The current protocol is three to four weeks between doses for the vaccines Pfizer, Moderna and AstraZeneca. Johnson & Johnson is a single dose vaccine but has not yet been approved in Canada.
The National Immunization Advisory Committee said the dose range would be extended to four months so that as many as 80% of Canadians over the age of 16 could receive a single dose by the end of June, simply with the expected supply of Pfizer-BioNTech and Modern vaccines. .
The second dose will begin administration in July as more shipments arrive, the panel said, noting that 55 million doses are expected to be delivered in July, August and September.
By comparison, the federal government had earlier said 38% of people would receive two doses by the end of June.
“I think they make a reasonable calculation in a time of drug shortages,” said Dr. Andrew Morris, a professor of infectious diseases at the University of Toronto and medical director of the Antimicrobial Stewardship Program at Sinai University’s Health Network. . “I think this is the right decision. Let me ask … A couple gets two vaccines. Do you give two to one, or do you give one dose? This is a no brainer. ”
The addition of the newly approved AstraZeneca vaccine to the country’s offering could mean that almost all Canadians would get their first chance at that time.
“The efficacy of the vaccine of the first dose will be closely monitored and the decision to delay the second dose will be continuously assessed on the basis of monitoring and efficacy data and study designs after implementation,” the panel wrote.
“The effectiveness against variants of concern will also be closely monitored, and recommendations may need to be reviewed,” he said. 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 in Canada.
The committee’s recommendation comes hours after Atlantic Coast Province Newfoundland and Labrador said it would extend the first- and second-dose interval to four months, and days after health officials in the Pacific Coast province of British Columbia announced they would do so. .
Manitoba and Quebec also said Wednesday they will delay the second doses. And the health minister in Ontario said it would want to deploy Ontario to vaccinate quickly.
Earlier Wednesday, Trudeau said any change in public health guidelines regarding the timing of the two doses could affect the speed of vaccination Canada, as well as the approval of more vaccines such as Johnson and Johnson.
Canada’s provinces administer health care in the country, so it’s ultimately the provinces.
Dr Brad Wouters, executive vice president of science and research at University Health Network, doubts the recommendation. ‘Nobody in the world has been between doses for four months. These are RNA vaccines that have never been used before. We need to use evidence to make decisions. Canada that did a population experiment, “Wouters tweeted.
And Mona Nemer, the federal government’s chief scientific adviser, 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 from three to four weeks. between doses.
But dr. Bonnie Henry, provincial health officer of British Columbia, said the manufacturers structured their clinical trials to get the vaccines on the market as quickly as possible, but said research in British Columbia, Quebec, Israel and the UK showed that the first doses are very effective.
Dr Supriya Sharma, chief medical adviser to Health Canada, the country’s regulator, told the Canadian Broadcasting Corporation in a time of limited supply that they were beginning to find greater comfort with the idea of waiting for the second dose after seeing actual data. has versus the strict interpretation of the clinical trials.
“In the real world, we’re starting to see evidence of other countries delaying the second dose.” Oh, they still seem to have a very good effectiveness. “We have laboratory studies showing that the immune response is unlikely to decline,” Sharma said.