The CDC said last week that it would accept any vaccine authorized for use by U.S. regulators or the World Health Organization. “While CDC has not recommended mixing types of vaccine in a primary series, we recognize that this is increasingly common in other countries so should be accepted for the interpretation of vaccine records,” a CDC spokeswoman said.

The White House said Friday the new vaccine requirements for foreign nationals traveling to the United States will begin Nov. 8 for visitors crossing at land borders as well as international air travelers.

Representative Brian Higgins, a New York Democrat representing a district along the Canadian border, had on Friday asked the CDC if it would accept the mixed vaccine doses noting “nearly four million Canadians, equivalent to 10% of their fully vaccinated population, have received mixed doses of the available mRNA COVID-19 vaccines – this includes the AstraZeneca vaccine.”

The CDC said the vaccines approved by the Food and Drug Administration (FDA) for use, as well as those authorized by the WHO, will be accepted for entry into the United States, including the AstraZeneca vaccine.

The CDC said “individuals who have any combination of two doses of an FDA approved/authorized or WHO emergency use listed COVID-19 two dose series are considered fully vaccinated.”

The CDC plans to answer other questions and release a contact tracing order for international air visitors by Oct. 25.