The Biden administration outlined on Monday very narrow exemptions that will permit unvaccinated international travelers to enter the United States.
Anyone who is under the age of 18 traveling from overseas will need to show a negative COVID-19 test before boarding a flight, but are exempted from vaccination requirements, the White House said.
Even though there are vaccines available in the U.S. to children as young as 12, administration officials said they are sensitive to the global variability regarding access to vaccination for older children who are otherwise eligible to be vaccinated.
Similarly, the White House said people who are traveling on non-tourist visas from countries that have vaccinated less than 10 percent of their population are also exempt from the vaccine requirement. There are more than 50 countries that meet that threshold, including much of Africa, according to the World Health Organization.
A senior administration official said those individuals would need to show a "compelling reason" for traveling to the U.S.
"They need to have a specific, compelling reason. So, tourist visas will not qualify for that," the official said. If they qualify, they need to show proof of a negative test taken within 24 hours prior to departure.
Other exemptions include those with certain medical conditions, clinical trial participants and those traveling on short notice for emergency or humanitarian reasons, the official said.
Most non-U.S. citizens and nonimmigrants arriving into the country by air will need to show both proof of vaccination and proof of a negative coronavirus test taken at least three days before departure.
The administration initially outlined the new rules for international travel in September, including a rule that unvaccinated Americans will need to provide proof of a negative coronavirus test taken no more than 24 hours prior to departure.
There will be no quarantine requirement, but airlines will collect data for enhanced contact tracing. Airlines will also be the primary enforcers for the testing and vaccination requirements.
Digital and paper proof will be accepted, provided they meet Centers for Disease Control and Prevention specifications and show the person was fully vaccinated. The definition of "fully vaccinated" means at least two weeks after receiving the final dose, whether it's a single dose or two-dose vaccine.
The CDC definition does not include proof of recent infection, with or without a vaccine.
"Initially there may be things that are more manual in nature and perhaps more paper. But as carriers are able to bring online more digital systems, we probably will see the use of those types of systems increase," a senior administration official said.
The U.S. will accept any of the vaccines authorized for emergency use by the World Health Organization even if they are not cleared in the U.S., including Russian and Chinese vaccines.