The last U.S. airline to maintain a social-distancing policy of leaving middle seats empty to lower COVID-19 risk is set to start filling them next month, just weeks after a new federal study found evidence that greater spacing can greatly reduce virus transmission.
The U.S. Centers for Disease Control and Prevention study published last week comes as air travel rebounds amid falling virus case rates, looser travel restrictions and more people getting vaccinated. And that invites another look at the question on many travelers' minds during the pandemic: How safe is it to fly?
The CDC study noted that because aircraft can hold large numbers of people in close proximity for long periods, there is increased risk for transmitting infectious diseases like COVID-19. A recent investigation of an international flight found that 75% of passengers who became infected after the flight were seated within two rows of a symptomatic passenger who likely originated the outbreak, it said.
The latest study found that based on laboratory modeling of exposure to the virus on single-aisle and twin-aisle aircraft, leaving the middle seats vacant reduced exposure from 23% to 57% depending on the configuration, compared with full aircraft occupancy.
"Physical distancing is difficult on crowded flights, and sitting within 6 feet of others, sometimes for hours, might increase risk," the study said. "Physical distancing of airplane passengers, including through policies such as middle seat vacancy, could provide additional reductions in risk for exposure."
The CDC study noted that the effect of wearing face masks was not considered in the analysis, which focused on aerosol exposure, because masks are more effective at reducing exposures through tiny respiratory droplets.
But it also said that a case study of COVID-19 transmission on a flight with mandated mask wearing "suggests that some virus aerosol is emitted from an infectious masked passenger, such that distancing could still be useful."
The airline industry has sharply disputed the suggestion it is putting profits ahead of passenger safety and said that the hospital-grade air filtration systems aboard aircraft, sanitizing policies and mask wearing have been shown to make flying safe.
"U.S. airlines have implemented multiple layers of measures aimed at preventing virus transmission, including strict face covering requirements, pre-flight health-acknowledgement forms, enhanced disinfection protocols and hospital-grade ventilation systems," the industry group Airlines for America said in a statement.
The industry group points to several studies including one by the Harvard T.H. Chan School of Public Health, Aviation Public Health Initiative that said the measures taken by the airlines reduce the risk of transmission of the virus aboard aircraft "below that of other routine activities during the pandemic, such as grocery shopping or eating out."