Canadian officials have been giving the United States, among other key travel destinations, data on the effectiveness of mixed vaccine doses in the hopes of getting those countries’ borders eventually opened to all vaccinated travellers.
As countries around the world try to figure out their international vaccine requirements, millions of Canadians have found themselves in an unusual predicament — not all governments consider someone with two different vaccine doses to be fully vaccinated.
But Canada is doing “everything that we can” to get other health authorities to accept travellers with two different doses, Dr. Theresa Tam, the country’s top medical officer, said Friday.
The White House announced this week that most adult foreign nationals will have to be fully vaccinated against COVID-19 by early November if they want to fly into the United States.
What’s not clear yet is what this policy will mean for Canadians who have always been able to fly south of the border, or how it will affect the land border, which remains closed to non-essential travel until at least Oct. 21 — or what it means for people who have two different vaccine doses.
The American government mostly doesn’t recognize the vaccination status of people who have two different shots.
Over the summer, Canada started allowing people to mix Moderna and Pfizer, which are both created using the same mRNA platform. Because of concerns about very rare blood clots, Canada was also one of the very few places to advise people who’d had a first shot of AstraZeneca to follow it up with one of the mRNA vaccine doses.
The result has been travel headaches for some Canadians who have ventured out of the country only to find their official vaccination status in doubt.
While mixing mRNA vaccines — meaning Moderna and Pfizer — is slowing gaining recognition, this has been a particular challenge for people who have an AstraZeneca dose and something else.
Everyone from cruise lines, to large event venues, to popular vacation spots, such as Barbados, have been slow to recognize mixed doses.
Canadians can currently fly to the States with a negative COVID-19 test. It wasn’t clear when the recent announcement was made how the new policy, which requires proof of vaccination and a negative test no more than three days old, will apply to Canadians.
It’s a similar rule to the one Canada began imposing this summer, first on citizens returning to the country, then eventually on all foreign nationals.
But the question mark is the American stance on mixed doses.
The American Centers for Disease Control and Prevention (CDC) website states that “COVID-19 vaccine products are not interchangeable,” but does say that you can mix the two mRNA shots, meaning Pfizer and Moderna, in “exceptional” circumstances.
It’s not that other countries think the approach doesn’t work — in fact, several studies suggest it is an effective strategy — but they may not have any data on it, because they aren’t doing it themselves.
With plentiful supplies of mRNA vaccines, the United States never used AstraZeneca at all, Tam points out.
That void has prompted Canada to step in and provide its own data.
About 3.9 million people in Canada have received a mixed-dose regimen of COVID-19 vaccines, with an estimated 1.4 million of them having received an AstraZeneca dose, Public Health Agency of Canada data indicates.
More than 223,000 people are fully vaccinated with AstraZeneca.
“Some of the European countries have already accepted this mixed schedule because they themselves also utilize such schedules, but we still have to advise travellers that they must check in with the specific country requirements prior to travel because it is a bit of a varied landscape out there,” Tam said.
To that end, Canadian officials have provided information to their counterparts at the (CDC) and other agencies south of the border.
American officials are still “in the process of deliberation,” she said.
With files from The Canadian Press
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