Aircraft passengers are up to three times more likely to contract the Omicron variant of the coronavirus compared to the Delta variant, a top medical adviser to the world’s airlines said on Tuesday.
"Whatever the risk was with Delta, we would have to assume the risk would be two to three times greater with Omicron, just as we’ve seen in other environments. Whatever that low risk—we don’t know what it is—on the airplane, it must be increased by a similar amount," Powell said.
Powell, who is a former chief medical officer at Air New Zealand, urged passengers to take safety precautions when onboard flights, including avoiding common touch surfaces, washing and sanitizing hands whenever possible, social distancing, wearing masks, and trying to avoid face-to-face contact with other customers.
The medical adviser recommended trying not to take off masks throughout the entire flight, even for meal and drink services, unless absolutely necessary.
"The advice is the same, it’s just that the relative risk has probably increased, just as the relative risk of going to the supermarket or catching a bus has increased with Omicron," he said. "The greatest protection you can give yourself is to be vaccinated and boosted. The protection that you give yourself from an extra mask or a different type of mask, or not flying at all, frankly, is probably less than the benefit you would get from just being fully boosted."
"There’s a sort of a rule of thumb starting to appear, that essentially Omicron loses you one vaccine dose of benefit. So, two doses against Omicron is about similar protection to one dose against Delta," Powell said. "That’s not established in hard science, but it roughly seems to correlate with what’s coming out in studies."
All three Airline CEOs noted that the majority of aircraft are fitted with high-efficiency particulate air (HEPA) filters that remove 99.99 percent of airborne particles onboard flights.
"I think the case is very strong that masks don’t add much, if anything, in the air cabin environment. It is very safe and very high quality compared to any other indoor setting," Southwest’s Kelly said.
United’s Kirby said that his company, alongside medical experts, had concluded that "effectively anywhere that you’re going to be indoors, the airplane is the safest place that you could be indoors because of the air filtration system. … Far safer than a theater, far safer actually than an intensive care unit, because we have HEPA-grade filters but we filter the air 20 to 30 times an hour and in a typical ICU, it’s two to three times an hour."
"Aircraft are a remarkably safe environment," he said, adding that sitting next to someone on a flight is the equivalent of being "15 feet away from them in a typical building."
However, Sara Nelson, president of the Association of Flight Attendants, noted that not all aircraft are equipped with the same quality of air filters, and encouraged both passengers onboard flights as well as staff to continue wearing masks as part of a "layered safety protocol."
Powell told Bloomberg on Tuesday that while airplanes are an enclosed space, they are not as risky as other places such as pubs and gyms.
"It is an enclosed space, but that doesn’t shout 'risk' to me," he said. "An Irish pub with a fan in the corner shouts 'risk' to me or a gymnasium with a whole lot of people shouting and grunting and sweating. But any flight you take does involve airports as well, which are a little bit less controlled. So, there is risk there."