Fully vaccinated travelers can come to the U.S. even if their doses are mixed, authorities say

The White House said U.S. travel restrictions will be lifted Nov. 8 for fully vaccinated international travelers, a policy that will in part require foreign travelers to show proof of vaccination before boarding a flight. According to a Friday update to CDC guidance, individuals will be considered fully vaccinated if they receive vaccines approved by the Food and Drug Administration or by the World Health Organization - including combinations of such shots.

That means international travelers will be considered fully vaccinated two weeks after they receive an FDA- or WHO-approved single-dose vaccine, such as the Johnson & Johnson shot, or "any combination of two doses of an FDA approved/authorized or WHO emergency use listed COVID-19 two-dose series," such as the Oxford-AstraZeneca vaccine.

While the CDC said it has not recommended mixing and matching vaccines, it acknowledged that "use of such strategies (including mixing of mRNA, adenoviral, and mRNA plus adenoviral products) is increasingly common in many countries outside of the United States."

Rep. Brian Higgins, D-N.Y., whose district along the Canadian border includes Niagara Falls and Buffalo, said the CDC's guidance was updated after he wrote a letter to CDC Director Rochelle Walensky requesting a clarification on its policies.

"Clarity is needed on which vaccines the United States will accept when the border reopens to all fully vaccinated Canadians," Higgins wrote Thursday. "Nearly four million Canadians, equivalent to ten percent of their fully vaccinated population, have received mixed doses of the available mRNA COVID19 vaccines - this includes the AstraZeneca vaccine."

In an interview Sunday, Higgins told The Washington Post that his office communicated with the CDC before sending the letter, and that the agency indicated that it was "working on it."

Higgins welcomed the "long-overdue" update but criticized the rollout of the federal government's travel rules.

"This border should have been open months ago," he said, adding that "both sides of the border have been hurt economically and have been hurt emotionally and have been hurt in terms of quality of life."

He said the guidance clarifying which vaccines will be allowed is "helpful, but again these are stand-alone issues that have confused people."

"It was inevitable that the border was going to open at some point," Higgins said. "All of these issues should have been anticipated and discussed and finalized so both the U.S. and Canadian governments and public health officials can speak with one, clear, concise message. That's still not happening."

He also criticized the testing requirements for travelers coming into the United States.

Higgins's office said he would "continue to seek answers to questions related to what the screening process will look like and will advocate for the removal of arduous testing requirements which he views as redundant for the vaccinated and an obstacle to the mutually beneficial binational exchange between Canada and the United States."

The CDC's website notes that fully vaccinated air travelers coming into the United States from abroad will be required to have a negative coronavirus test result before boarding a flight into the United States. Those traveling by land do not need to provide a negative test.

Anthony J. Santella, professor of health administration and policy at the University of New Haven in Connecticut, said the CDC's guidance allowing mixed vaccine doses "is a smart thing to do if you want to open your doors again."

"If we're really serious about being okay with domestic and international travel, we have to be willing to accept that not every country does the same thing and has the same kind of vaccination policy," he said.

Santella said the CDC's guidance suggests that U.S. officials are "choosing to accept that these vaccines largely work and that we'll err on the side of 'If you're vaccinated, regardless of what vaccine it is, you're welcome here,' and to let science continue to take its course."

The updated guidance comes as a U.S. coronavirus surge wanes, though public health experts are bracing for the possibility of a "twindemic" of covid and the flu season.

More than 59,000 people in the United States are hospitalized for treatment of covid-19, according to data tracked by The Washington Post, with coronavirus-related hospitalizations falling 7.5% in the past week. There were more than 100,000 new coronavirus cases reported Friday, with new daily reported cases dropping more than 13% in the past week.