On October 25, 2021, President Biden announced a presidential proclamation titled “A Proclamation on Advancing the Safe Resumption of Global Travel During the COVID-19 Pandemic”. Effective on November 8, 2021, at 12:01 am (ET), the proclamation moves away from country-by-country travel restrictions and adopts an air travel policy that relies primarily on vaccination, with limited exceptions.
The memo states:
This proclamation governs the entry into the United States of noncitizen nonimmigrants — that is, noncitizens who are visiting the United States or otherwise being admitted temporarily — traveling to the United States by air. It suspends the entry of unvaccinated noncitizen nonimmigrants, except in limited circumstances, and it ensures that the entry of unvaccinated noncitizen nonimmigrants is consistent with applicable health and safety determinations made by the Director of the CDC, including a requirement that, where appropriate, such individuals agree and arrange to become fully vaccinated against COVID-19 upon their arrival.
See also,
White House Fact Sheet on New Requirements
FAQs on New Requirements for Vaccination Prior to International Travel
Requirement for Proof of COVID-19 Vaccination for Air Passengers