The Public Health Agency of Canada says it’s working with other governments still dubious about allowing Canadians with mixed vaccines to travel across their borders without quarantining. Several countries, including the United States, only recognize people with two identical doses of an approved vaccine as being fully vaccinated.

Dr. Theresa Tam, Canada’s chief public health officer, says PHAC has presented data on the effectiveness of mixed doses to the US and other top-priority destinations.

She says Canada has been particularly active in spreading information about the effectiveness of mixing Oxford-AstraZeneca with mRNA vaccines like Pfizer-BioNTech and Moderna.

Many countries don’t have domestically generated data on that front, so Canada is working to help them make decisions about their own tourist regulations.

The federal government is expected to release more details about a standardized vaccine passport for Canadians in the coming weeks.