April 16, 2021 -- As Americans travel again and airlines begin filling their planes to capacity, the CDC says blocking the middle seats on commercial airliners could reduce the transmission of COVID-19 by 23% to 57%.
Researchers studied laboratory models of single-aisle and double-aisle aircraft using aerosol dispersion as a surrogate for the coronavirus, according to findings reported Wednesday in the CDC’s Morbidity and Mortality Weekly Report.
The risk reduction was 23% for a single passenger sitting in the same row and two seats away from an infected person, rather than in an adjacent seat, the study said.
A 57% risk reduction was found when the middle seat was vacant in a three-row section that contained a mix of infected and non-infected passengers.
“Physical distancing of airplane passengers, including through policies such as middle seat vacancy, could provide additional reductions in risk for exposure to SARS-CoV-2 on aircraft,” the CDC concluded.
One limitation of the study, researchers said, was that it did not measure the impact of wearing face masks.
The study, conducted by the National Institute for Occupational Safety and Health (NIOSH) and Kansas State University, comes out as almost all U.S. airlines pack their planes -- and lift middle seat blocks -- in an attempt to recoup financial losses suffered during the height of the pandemic.
Delta Air Lines will be the last to unblock middle seats -- on May 1.
An air industry analyst doesn’t expect the airlines to block middle seats again.
“This is a giant bombshell from the CDC,” Henry Harteveldt, co-founder of Atmosphere Research Group, told The Washington Post. “I think the airlines are going to look at it and say, ‘That’s nice. We’re not going back to blocking middle seats.’”
Business Insider said it contacted several airlines for comment, including Delta Air Lines, American Airlines, and Southwest Airlines. Those airlines deferred to Airlines for America, a trade organization.
"Multiple scientific studies confirm that the layers of protection significantly reduce risk, and research continues to demonstrate that the risk of transmission onboard aircraft is very low," a spokesperson for Airlines for America said, indicating no changes would be recommended to airlines, Business Insider reported.
The CDC said early in April that people who are fully vaccinated can now safely travel with low risk for COVID-19 transmission.
The new guidance specifies that travelers should still wear a mask, socially distance, and practice thorough hand hygiene. The new CDC guidance also says that fully vaccinated people can travel within the U.S. without getting tested for the coronavirus or quarantining, and do not need to get a COVID-19 test before leaving, though some destinations may require it.
The CDC said people who are fully vaccinated and returning from international travel should get tested and have a negative result before they board a flight back to the United States.