(CNN) — Mask mandates in the United States are speeding toward what could be their final frontier: transportation.
Airlines including Delta, American, United and Southwest, plus cargo carriers and industry group Airlines for America, are all calling for an end to both the mask mandate on public transportation and the pre-travel testing requirement for international arrivals to the United States.
"It is past time to eliminate Covid-era transportation policies," they said in a recent letter addressed to the White House.
The nation's largest flight attendants union, the Association of Flight Attendants-CWA, hasn't come down on one side or the other of lifting the mask mandate -- saying it has members on both sides of the issue. Southwest Airlines' flight attendants union has called for an end to the mandate.
Many in the travel industry are understandably eager to make it as easy as possible to get more travelers moving after two crippling years of the pandemic.
But how do doctors and disease transmission experts regard the rollback of Covid precautions? It's not all or nothing, for one thing.
Travelers can still protect themselves, and the rules could be eased incrementally or reinstated if cases increase substantially. Cases in the United States have plateaued recently after nearly two months of declines, and health officials are keeping a close eye on the BA.2 Omicron variant.
Lift the rules for vaccinated travelers, one doctor suggests
Dr. Leana Wen, a CNN medical analyst, says lifting both the mask mandate and pre-travel testing requirement for international arrivals makes sense -- for vaccinated travelers.
Allowing fully vaccinated people to bypass the requirements gives them another incentive to get vaccinated, said Wen, an emergency physician and visiting professor at George Washington University Milken Institute School of Public Health.
While the letter from airlines to the White House didn't specifically call out vaccinated travelers, it did cite a World Health Organization recommendation for a risk-based approach of "lifting measures, like testing and/or quarantine requirements for individual travelers who are fully vaccinated."
Right now, all travelers heading into the United States, regardless of citizenship or vaccination status, must have a negative result from a test taken within one day of departure. Lifting that requirement is the most immediate, "right step" that could be taken for fully vaccinated travelers, Wen said.
"There are so many people who are putting off their international travel plans because they don't want to have a positive PCR test and then be stuck for weeks ... at their destination."
Wen also suggested that airlines could designate a section of the plane where people who want extra protection and agree to wear N95 or equivalent high-quality masks can sit together.
There are no easy answers at this point in the pandemic, Wen said.
"And the question is -- how should flights be considered? Are they considered something essential, in which case you do want to give vulnerable people the option to feel extra safe or is it considered like dining out in a restaurant, where if you choose to dine, you're taking on an added risk yourself?"
Wen believes air travel should be considered essential because many people are traveling out of necessity.
"And so that's why providing that option to be additionally safe is the right thing to do."
Make masks optional
From Dr. William Schaffner's point of view, it makes sense to lift both the masking and pre-travel testing measures now.
"I mean if there's a reason not to do it, let's hear it," said Schaffner, an infectious diseases specialist at Vanderbilt University Medical Center in Nashville, Tennessee.
Schaffner pointed out that the CDC has changed the metrics that inform its masking recommendations within the United States, and some medical professionals see a disconnect when it comes to maintaining stricter standards for travel.
The airlines' argument for lifting the mask mandate mirrors that point.
"It makes no sense that people are still required to wear masks on airplanes, yet are allowed to congregate in crowded restaurants, schools and at sporting events without masks, despite none of these venues having the protective air filtration system that aircraft do," their letter to the president reads.
Testing international arrivals doesn't make much sense to Schaffner either.
"I've been bemused about that for a long time because we've got plenty of Covid here! It's not as though we're trying to keep Covid out," Schaffner said, chuckling. "It's here already."
"I've always thought that this was a little like telling someone not to pour a bucket of water into your swimming pool."
But he emphasized that people may choose to wear masks and their choices should be respected.
He and his wife are caring for an extended family member who is receiving chemotherapy, and they continue to wear masks and be very cautious to protect that person.
"I think the larger world, I hope, has some understanding of that and not only tolerates it but supports it," Schaffner said.
An aerosol expert weighs in
Linsey Marr, an expert in transmission of infectious disease via aerosols, said via email that dropping the mask mandate is reasonable with the caveat that it makes sense "as long as cases remain low."
"There is a smaller chance that someone who is infected will be on the plane. And we know that planes have excellent ventilation and filtration, which help reduce the risk of transmission on a plane," said Marr, who is a professor at Virginia Tech.
Those who want more protection can still choose to wear a high-quality mask on planes, which Marr said she intends to do during future surges and during cold and flu season. And bringing mandates back should be on the table.
"The virus has been very unpredictable, and we should be prepared to bring back a mask mandate if cases rise again or a new variant of concern emerges."
Continue to exercise caution and care
Dr. Richard Dawood, a London-based travel health specialist, has a more tentative view of lifting testing and mask requirements.
The United Kingdom, where cases crept up recently because of the BA.2 subvariant, has already dropped vaccination, testing and quarantine requirements for travelers, and several air carriers have recently announced an end to mask rules -- at least for destinations that don't have their own mask mandates.
If it were up to him, he probably wouldn't lift Covid precautions for travel just yet.
"If you are traveling long haul, it's quite reassuring to be on a flight where you know people have had a pre-departure test," Dawood said.
Traveling right now should be approached with some caution and care, he said. Even if your risk of getting critically ill and landing in the hospital while you're away is slim, getting sick could significantly disrupt your trip.
"I think I shall certainly continue using a mask for my own protection, especially if I'm going long haul."
This article originally appeared on CNN