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The Centers for Disease Control and Prevention ended COVID-19 testing for airline passengers arriving to the U.S. from abroad. Why did they do that? Should I test anyway? And when?

Years from now, when Americans talk about foreign vacations during the pandemic era, they'll recall the rush for souvenirs, that extra suitcase ... and paying someone to stick a swab up their nose for the compulsory pre-flight COVID-19 test.

But now, that COVID test before travel won't be necessary. As of June 12, the CDC no longer requires any passengers arriving to the U.S. to show a COVID recovery certificate or take a COVID test before traveling to the U.S. (Non-U.S. citizens, with few exceptions, must show proof of vaccination.)

The CDC first put its testing rule in place in January 2021, which required a PCR or supervised antigen test within three days of travel. In November 2021, the CDC shortened the testing period to 1 day for people who were not fully vaccinated. Then in December 2021, the agency required that a viral test be done one day before the flight for all passengers.

Last week, the CDC explained in its announcement why it was now ending the testing requirement. Uptake of the highly effective COVID-19 vaccines, effective therapeutics and a high rate of vaccine- and infection-induced immunity all contributed to lower risk of severe disease and death across the U.S., according to the agency. As a result, the CDC said the testing requirement, which was needed at an earlier stage of the pandemic, could be withdrawn.

But the announcement also recommended that travelers boarding a flight to the U.S. take a viral test within three days of travel — and not travel if they are sick. And long-standing CDC guidance has recommended testing three to five days after the flight in case you picked up the virus during travel.

Why you should test before flying to the U.S.

It's a good idea to take a COVID test before boarding a flight to the U.S. – even though it's no longer required — for a number of reasons, says Gigi Gronvall, an associate professor in the Department of Environmental Health and Engineering at the Johns Hopkins Bloomberg School of Public Health.

Knowing your COVID status can help you decide whether it's safe to travel or whether to push back your flight, says Gronvall. For tourists, it can reduce the chance of you feeling ill on your vacation. And it can prevent other passengers from getting COVID in transit. "It's especially important if you are at risk of severe disease because of age or underlying health conditions," she adds.

How to test now

The best time to test before a flight, or any other event, is as close to the start time as possible. That's because test results "are just a snapshot in time," says Gronvall. A minute after getting negative results, you could be exposed to someone with the virus and suddenly be infected with COVID-19. For a flight, you might take a test a day before so that you're not changing all your travel plans at the last minute if you test positive.

Because the tests are now voluntary, it's up to you to decide what kind of viral test you'd like to take. While PCR tests are likely to be more accurate, it can take a day or more to get them back. So many people are going to take a rapid antigen test, which shows results in less than 15 minutes but can be give a false negative result if someone has a lower viral load – say, if they were very early in the course of their infection. Still, these at-home tests can be trusted if you get a positive result. They give false positives extremely rarely.

You're probably best off taking a few rapid antigen tests with you on your trip. If possible, choose tests you've used before to minimize confusion and stress while you're away. And keep the tests in their original packaging, even if it means you have to jettison other items in your suitcase, so that you're sure you have all the components and instructions. Use these tests when necessary – for example, if you've had a COVID exposure — and before you get on the airplane, says Daniel McQuillen, an infectious disease specialist at Lahey Hospital & Medical Center in Burlington, Mass.

What to do if you test positive

If your test comes back positive while you are at your destination, you will need to isolate and postpone your return to the U.S. until it's safe for you to travel, says Jasmine Reed, a CDC spokesperson. Your travel companions may need to quarantine, too. Follow all COVID recommendations and requirements at your local destination, she adds.

The CDC says it's best to avoid travel for a full 10 days after your last exposure to someone with COVID-19. But if you must travel during days 6 through 10 after your last exposure, then:

Make sure that you can access health care while abroad. Talk to your doctor ahead of your trip to ask how to reach out if you test positive while out of the country. And make sure you have health insurance that will cover care if you need a doctor's visit, medication or hospitalization if you get COVID-19 abroad. If your insurance policy covers care overseas (Medicare and Medicaid generally do not) ask for a letter that states that and have your insurance card with you. The State Department has information on buying coverage for care overseas.

Don't ask for Paxlovid before you fly

You may have heard that there's a drug that can help reduce the risk of progressing to severe disease if you do contract COVID-19 — and may wonder if you should pack it in your travel bag. Paxlovid received an emergency use authorization from the Food and Drug Administration in December 2021 for people at risk of severe COVID, including hospitalization and death, because of risk factors such as age, obesity, diabetes and other chronic conditions.

But experts, including Raymund R. Razonable, vice chair of infectious diseases at the Mayo Clinic, advise against it. For one thing, says Razonable, under the drug's EUA it can only be prescribed based on a positive viral test. Razonable says he's had requests for the drug from people pre-travel, but he's turned them down both because that's in violation of the EUA and because the drug can be hard to manage. Paxlovid can have negative interactions with dozens of drugs, including vitamins and supplements. Patients who take it must work with their doctor or pharmacist to decide whether they can be off of certain drugs or reduce the doses for the five days of the drug's course.

How to stay safe while traveling

Wearing a mask in indoor public spaces, like a plane, remains a good idea, says Gronvall. If people don't feel like wearing it the whole time on a flight, they should at least consider wearing it during boarding and deplaning. "Often, air crews shut the air off then — so circulation of air, [which can help prevent virus transmission], goes way down, and that's also when people are more crammed together."

McQuillen also reminds people to take masks with them on any trip and to wear them in indoor public settings like airports to avoid getting sick while traveling. And make sure you've had your full vaccine doses and at least one booster dose, he says. That's to ensure that if you do get COVID abroad, it's likely to be less severe. "The vaccines are engineered to prevent ICU-level disease and death."

Fran Kritz is a health policy reporter based in Washington, D.C., and a regular contributor to NPR. She also reports for the Washington Post and Verywell Health. Find her on Twitter: @fkritz

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