Unraveling Booster and Vaccine-Timing Rules for International Travelers

The requirements for entering foreign countries during the pandemic can be confusing and ever-changing, especially when it comes to boosters. Here’s what to expect.

The requirements for entering foreign countries during the pandemic can be confusing and ever-changing, especially when it comes to boosters. Here’s what to expect.

Mr. Henretta said he thought he was doing the smart thing by getting his booster when he did. “The real irony is that I made the earliest approved appointment and then it comes back to bite me,” he said.

Switzerland is an outlier in limiting boosted visitors in this way. But other governments have also begun to put time limits on how long a visitor is considered fully vaccinated with just one or two doses.

Mr. Henretta’s situation offers a particularly thorny illustration of just how confusing and changeable vaccination rules are becoming. Here is a look at how some of these new requirements are playing out across the world.

Do other countries put a time limit on vaccinations and boosters?

Yes, but most still allow visitors into the country.

Malta, for example, puts a time limit on shots. Those who have received two doses must have gotten their last shot within three months. Boosters expire after nine months. But unlike the situation in Switzerland, it’s still possible for travelers with a timed-out vaccine to enter. Those individuals are treated as if they are unvaccinated, meaning that they must present a negative P.C.R. test result and quarantine at a designated facility for 14 days after arrival.

Similarly, in Bulgaria, vaccination certificates are considered valid from the 15th to the 270th day after the last dose, with no apparent exception for boosters. But because unvaccinated people may enter, those who have timed out must simply show a negative Covid-19 test result to enter.

How do other types of vaccine expiration dates affect travelers?

In some cases — for example, in France and Estonia — there are time limits on the validity of full vaccinations without a booster (nine months for France and a year for Estonia). Because these countries prohibit tourists from the United States and some other countries from visiting if they are not fully vaccinated, that means that a traveler who got their second Moderna shot before May 17 can’t enter France unless they first get a booster. Having a booster makes things easier when it comes to timing constraints since these places treat boosters as a sort of expiration-free additional dose.

Ireland and the Czech Republic treat anyone who got their second dose more than nine months ago as if they are unvaccinated. Croatia takes the same approach, but makes it more than a year. But their governments do not prohibit unvaccinated American tourists from entering. A traveler who got their second Moderna shot before May 17 could take a test or get a booster to enter these countries.

Are there any countries that require being boosted for entry?

Not currently.

Austria, for example, does not consider someone fully vaccinated unless they’ve had the booster. But travelers who do not meet that requirement can still enter the country by obtaining a negative result from a P.C.R. test.

Why do countries impose these time limits?

One reason, Ms. Bonga said, is to encourage people to get boosters.

There is also some evidence that coronavirus vaccines stop providing as much protection as time goes on.

What if different entities and sites are giving me conflicting information?

This may happen. Getting the answer to Mr. Henretta’s query about traveling to Switzerland, for example, was far from straightforward. The fact that the last shot of a vaccine timed out after 270 days was clear, but some sources could not agree on whether unvaccinated Americans could enter the country or not. A representative for the country’s information line for travelers suggested that they could; in that case, Mr. Henretta could simply provide a negative test result. Swiss International Air Lines initially offered the same answer on its site and by email. But the State Secretariat for Migration, two representatives from the Swiss tourism office, and the official Swiss entry tool took a different position: Unvaccinated and partially vaccinated American tourists could not enter. Eventually, a representative from Swiss International Air Lines clarified that although unvaccinated visitors from some countries can enter with a test, unvaccinated Americans cannot because the United States is currently classified as a high-risk country.

In the end, almost everyone was finally in agreement: Mr. Henretta could not take his long booked flight unless a fourth shot becomes available or the rules change, which happen fairly frequently.

Source: Heather Murphy