During the holidays, Omicron variants have many people considering the possibility of getting stuck while traveling. This is what you need to know.

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Millions of Americans are expected to travel during Christmas and New Year, and some booking sites (such as Hopper) predict that even international travel will be close to pre-pandemic levels. When travelers try to decide whether to implement their plan, many people are trying to solve this problem: What if I get a vaccine but test positive, and then get stuck far from home?

This is not an outrageous question. According to data from the Customs and Border Protection Agency, more than 5 million people flew to the United States during the holidays in 2019. Everyone 2 years of age and older returning to the United States by air from abroad—including vaccinated U.S. citizens—must be tested for coronavirus within one day of returning home. Even if the number of travelers is far below the level of 2019, some people will still have to cancel flights to the United States because they test positive.

Of course, for people who are seriously ill with Covid, the immediate problem is far more than just getting stuck. In the past week, an average of 7,052 people worldwide (including nearly 1,300 in the United States) died of coronavirus every day. For people who have been vaccinated, the impact is usually less dire. When the intensive care unit in many places is overwhelmed, worrying about not being able to register makes people feel self-indulgent. But from a planning point of view, the consequences are not trivial.

Alas, even before the Omicron variant appeared in November, this was difficult to answer. Although studies have shown that the average American who is vaccinated every day has about one in 5,000 chances of contracting Covid, this number may increase with the popularity of Omicron.

Although there are still many unknowns about this variant, early signs indicate that it has a higher rate of infecting vaccinated people than previous variants. A small study found that most of the 43 people who initially found Omicron in the United States were vaccinated when they tested positive. There are some early signs that this variant may cause a milder disease than other variants, and scientists predict that people who are vaccinated are unlikely to become severe.

The booster should reduce the chances of the vaccinated person being infected with multiple variants. President Biden’s senior medical adviser, Dr. Anthony S. Fauci, said on Wednesday that early data showed that booster injections of Moderna and Pfizer-BioNTech vaccines can provide substantial protection against Omicron. Dr. Aaron Milstone, Professor of Pediatric Infectious Diseases at the Johns Hopkins University School of Medicine, said that the booster injection started to affect many people in just a few days, which means that even if you are traveling soon, it will not be too late. Doctor of Medicine, he is studying the immune response to booster doses. He and other experts pointed out that 10 to 14 days after the injection may provide stronger protection, so the sooner you get it, the better.

When driving across state borders, no one will ask you to show a negative test result. With a few exceptions: Hawaii and the U.S. Virgin Islands, states, airlines, airports, or most other means of transportation do not require domestic travelers to test negative for the coronavirus.

Dr. Emily E. Volk, President of the American Society of Pathologists, said that if you eventually test positive—perhaps because a private party requires testing—the responsible course of action is to isolate yourself from others because you are contagious. An organization of doctors who perform biopsies and diagnose diseases.

"This is morally and ethically correct practice," she said.

But in most parts of the United States, how to continue is up to the individual to decide. The Centers for Disease Control and Prevention recommends isolation for at least 10 days after testing positive, even if a person has never developed symptoms. In a recent article in The Atlantic, author Katharine J. Wu believes that this recommendation is outdated and that people who are vaccinated should be able to undergo isolation testing faster. Dr. David Friedman, the president-elect of the American Society of Tropical Medicine and Hygiene, made a similar point in a recent interview: Once the test result is negative, traveling again should feel good, he said.

Either way, for better or worse, these are just suggestions. Some employers, educational institutions, states and counties have additional isolation policies, but few places actively enforce isolation. Depending on where you test positive, you may receive a call from a contact tracker. Or you may not.

A key step in planning any trip is to familiarize yourself with the locations where you must be tested and what will happen if you or someone traveling with you test positive, including the length and type of isolation. In some destinations, the only specific consequence of a positive test is that you cannot board the plane. In other destinations, health officials may require you to stay in a government hospital for more than 10 days.

Amy Eckhardt, owner of World View Adventures, a travel agency in Buffalo, New York, recommends packing up as if you’re getting stuck. This may mean bringing two more weeks of medication and Work with laptop.

Ms. Eckhart has not yet tested positive for a client when she is abroad, but she has learned a lesson from her experience. Last winter, in order to celebrate her 40th birthday, she stayed in Mexico for a month and a half before she had the opportunity to be vaccinated. At the last stop of the trip, she chose a resort in Ladies Beach, which provides free on-site testing and pays for food and lodging during the isolation period when needed.

She said that when she tested positive on January 31, the hotel staff asked her to wear a "biohazard orange" wristband and moved from her waterfront room to a basement room in the "quarantine area." Because she was the first guest in the hotel to test positive, the staff is still trying to deal with this situation. Her resort sent a guard outside the door. Initially, she had to move to a new room across the hall every three days, while people in protective clothing and goggles disinfected the room and put new towels in the bathroom. .

Fortunately, she never experienced any serious symptoms. Her main obstacle was boredom, which she solved by posting detailed updates about iguanas on the terrace and posting other humorous observations in the travel agency’s private Facebook group. After completing the 10-day quarantine, she tested negative and flew back to the United States.

Dr. Friedman of the American Academy of Tropical Medicine and Hygiene said that people infected with Covid usually test positive within five to eight days.

He said that in rare cases, even if the person is no longer infectious, they may test positive for up to six weeks. In some cases, there is a way to solve this problem. Many countries and airlines will accept rehabilitation certificates issued by doctors or health officials in lieu of testing. Erika Richter, a spokesperson for the American Association of Travel Consultants, a trade organization, urged people to review the CDC's highly specific requirements for the certificate.

Dr. Volcker, president of the American Society of Pathologists, recommends that anyone at home or who has a positive antigen test should undergo a PCR test, which is more likely to give you a true positive result.

It depends on the type of insurance. My colleague Elaine Glusac explained in this article on travel insurance that some policies will cover additional air tickets and accommodation for up to 7 days after your original return date, effectively covering only a one-week quarantine period. Some policies will also cover medical expenses abroad, which are usually excluded from traditional health insurance policies.

It is wise to take various precautions before vaccination-avoid crowded indoor activities and wear masks.

Dr. Millstone of Johns Hopkins University School of Medicine said: “Vaccines do a great job of keeping people alive, but masks can prevent people from getting infected.”

It's also worth remembering that you need to start to be extra careful before traveling-if you are infected shortly before departure, you may not test positive before traveling.

Jenny Mikkelson, vice president of luxury safari company Travel Beyond, saw this. On the day after Thanksgiving, 10 Americans flew from Minneapolis to Cape Town. They all tested negative in the United States. In order to fly to Botswana for hunting, they had to undergo another test. One passenger tested positive. A few days later, the second American traveler living with the traveler also tested positive. Ms. Mickelson said that considering the time, the first traveler is likely to have been infected in Minneapolis. During the quarantine period in the luxury hotel, neither of them showed symptoms, but they missed the safari park. Once they all tested negative, they flew home.

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