While it's welcome news that the U.S. will reopen its shared land border with Canada to non-essential travel in early November, some Canadians with mixed vaccine doses aren't celebrating just yet.
That's because at the same time the U.S. reopens the land border, it will start requiring that foreign land and air travellers entering the country be fully vaccinated.
The U.S. Centers for Disease Control (CDC) currently doesn't recognize mixed COVID-19 vaccines — such as one dose of AstraZeneca, and one dose of Pfizer or Moderna — and hasn't yet said if travellers with two different doses will be blocked from entry when the vaccine requirement kicks in.
"CDC will release additional guidance and information as the travel requirements are finalized later this month," said spokesperson Jade Fulce in an email on Wednesday.
Millions of Canadians have mixed vaccines, including Brian Butler of Bowmanville, Ont., who received one dose of Covishield, a brand of AstraZeneca, and one dose of Moderna. He has two daughters and two granddaughters in the U.S., and is frustrated that the country hasn't confirmed yet if his vaccine mix will be accepted.
"Just make a decision," he said. "Someone with a mixed vaccination I don't think is a threat of spreading COVID in the States."
On Wednesday, Dr. Ali Khan, former assistant U.S. Surgeon General, told CBC News he believes the U.S. will likely update its guidelines to accept mixed doses, because studies have shown mixing vaccines is effective.
"The scientific community absolutely understands this," he said. "Essentially what we're waiting for now is a [U.S.] policy that aligns with that practice."
What does the U.S. say about mixed vaccines?
The United States' stance on mixed vaccines first sparked concerns last month, when the country announced that foreign air passengers entering the country will soon have to show proof they're fully vaccinated.
On Tuesday, it was revealed the U.S. would finally reopen its side of the land border to tourists, but that they too must be fully vaccinated. According to U.S. officials, Canadians crossing by land will be questioned about their vaccination status and must show documentation if they're sent for secondary screening.
"Individuals who have not been fully vaccinated for COVID-19 will not be allowed to travel for non-essential purposes from Canada," said the Department of Homeland Security in a statement.
So the burning question now is which vaccines will be accepted for travel to the U.S.
Last week, the U.S. Centers for Disease Control (CDC) confirmed that the country will accept visitors inoculated with COVID-19 vaccines authorized by U.S. regulators or the World Health Organization. WHO-approved vaccines include AstraZeneca and its Indian-made counterpart, Covishield.
A similar rule is expected at land crossings. But the U.S. is still waiting for guidance from the CDC about travellers with mixed doses.
While the CDC currently doesn't recognize mixed vaccines, there are some exceptions to the rule.
The CDC says on its website that mixed doses of the two mRNA vaccines, Pfizer and Moderna, are acceptable in "exceptional situations," such as when the vaccine used for the first dose was no longer available.
To understand how the current CDC guidelines are playing out, CBC News surveyed the vaccination policies of eight major cruise lines departing the U.S. Each cruise line said it will accept a mix of Pfizer and Moderna, but no other combination will do.
"For example, Canadian or other international guests who received a combination of AstraZeneca and Pfizer are considered unvaccinated by the CDC," states Carnival Cruises on its website.
The cruise line policies have already forced some Canadians with mixed vaccines to cancel their cruises.
Cruise ship entertainer, Michael Harrison of Windsor, N.S., said he and his fiancée, who works as his assistant, recently had to turn down offers to work on two different cruise ships, because they each have a mix of AstraZeneca and Moderna.
"It's just frustrating it worked out this way," said Harrison, who performs as a ventriloquist on cruises. "If we had known, we certainly would have not put ourselves in this position."
What's the prognosis?
Canada updated its vaccination guidelines in June to recommend mixing COVID-19 vaccine doses based on emerging research that found it was both safe and effective.
Meanwhile, the CDC maintains that "data on the safety and efficacy of a mixed-product series are limited."
But that could change.
The U.S. recently conducted a study exploring the effectiveness of using a different COVID-19 vaccine as a booster shot.
This week, U.S. authorities will meet to review the data which so far suggests mixing vaccines is safe and effective.
Khan said he believes the outcome will be a recommendation to recognize mixed doses.
"I personally can't think of any reason why they wouldn't do it."
But that still leaves Canadians with mixed doses — and travel plans — in limbo until a decision is made.
Eager to get back to work as soon as possible, Harrison said he and his fiancée plan to sign up for a third dose in Nova Scotia, so they can have two doses of Moderna. Starting Friday Oct. 15, people in Nova Scotia can get a third shot if they require it to travel for work.
"It's wonderful," said Harrison. "I'm hopeful that it's so quiet here in little Windsor [N.S.], that by the time October 15 rolls around, we'll be able to get online that morning and book a shot that day."
Quebec, Manitoba, Saskatchewan and Alberta each currently offer third vaccine doses to people in their province who need it for travel.
