The mask mandate is off for U.S. travelers. In other countries it's definitely on

The mask mandate for domestic U.S. flights has been lifted — although it might come back.

But what about the rest of the world?

Masking up is still a requirement with a number of airlines: Air France, Japan Airlines, Lufthansa, Pakistan International Airlines, South African Airways and Malaysian, to name a few.

"You must wear your mask at all times throughout the flight, except when eating or drinking," is Egyptair's position.

LATAM airline, based in Santiago, Chile, has a lengthy mask dissertation: "No passenger may board the aircraft without a mask, or without its proper use. The only exception is for children under 2 years of age and between 2 and 11 years old, for whom there is flexibility in the use of the mask. In case of refusal to use it before or during the flight, you will be reported as an unruly passenger to the respective authorities.

"Persons with a medical condition who cannot wear a face mask or cannot wear it safely due to the medical condition must send a medical certificate or the MEDIF form through our Contact Form at least 48 hours before the scheduled flight."

And not just any mask will do. On the no-no list:

Valved mask (any type)

Bandanas or bandanas

Plastic mouth guards

Fabric or reusable masks on flights within Chile.

China's airlines have become a bit less strict than in the early days of the pandemic – when in-flight announcements would urge passengers not to chitchat during the flight.

Nonetheless, a mask is not optional.

Passengers are required to wear medical surgical, KN95 or N95 masks from the time of check-in at the airport through the duration of the flight – and until you leave the airport.

In addition to masks, passengers are asked to bring their own gloves as an optional additional precautionary measure. (The authorities see gloves as a deterrent to infection even though the value of gloves as a pandemic measure has been debated and basically debunked).

There are other precautionary measures for air travelers in China. Your body temperature is measured when you enter an airport and again before boarding the plane. And there are still some inflight announcements about infectdion prevention — for instance, reminding passengers not to touch their face

In China and other countries you'll also need medical documents in order to fly. South African Airways requires that children over 5 and adults must have a negative PCR test taken 72 hours prior to departure for all international flights, and must complete a "Traveler Health Questionnaire" on arrival, asking such things as, "Did you change your seat during the trip?"

Flight crews have been subject to even more demanding requirements than passengers in many places. In India, for example, the Ministry of Civil Aviation set regulations as of May 2020 that all flight crew were required to be in PPE — a full protective body suit, (similar to the kind medical professionals wear) with masks, gloves and face shield. But in mid-March the rules were revised; PPEs are no longer required for cabin crew onboard. They still use shields and gloves.

Masks however, are still required for everyone, onboard all domestic flights.

The U.S. isn't the only country to have dropped mask requirements. The same thing has happened in some countries in Latin America: Brazil, Paraguay and Uruguay, for example.

According to the Brazilian report, the governor of Sao Paulo city, Joao Doria tweeted, "Finally without masks. The progress of vaccination and drop in hospitalizations and deaths allow us to take this measure."

But even as mask mandates for public transportation are debated – and sometimes dropped – many global health experts support them.

In a press conference on April 20, the director of the Pan American Health Organization, Dr. Carissa Etienne, noted: "The WHO's emergency committee last week declared that the COVID health pandemic still constitutes an extraordinary event that continues to adversely affect the health of populations around the world. It still poses an ongoing risk of international spread and requires coordinated international response ... so we are still in a public health emergency of international concern."

That's a position endorsed by Henry Wu, director of Emory TravelWell Center and an associate professor of infectious diseases at Emory University School of Medicine: "Airports see the greatest influx of people around the world. A mask can be the cheapest, simplest tool to protect you from infections in these situations."

"It's not a good time to drop the interventions that we know have been effective. It's too premature," says Mike Toole, a founding member of Medicins sans Frontiers in Australia and an associate research fellow at Burnet Institute whose work revolves around infectious diseases and international health. These interventions made travel safer and possible, especially for senior citizens during the pandemic, says Toole, who is age 75.

In fact, he thinks masking is more important than ever because governments may be relying on people to be responsible, self-test and not fly if they test positive for COVID. But testing isn't 100% accurate – and people aren't always 100% responsible for self-testing.

So what does the global mask scene mean for American fliers? Checking with any international carrier before heading to the airport is still critical, says Wu.

Kamala Thiagarajan is a freelance journalist based in Madurai, Southern India. She reports on global health, science, and development, and her work has been published in the New York Times, The British Medical Journal, BBC, The Guardian and other outlets. You can find her on twitter @kamal_t

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