Leaving middle seat vacant on planes can reduce SARS-CoV-2 exposure, study shows
Leaving the middle seat vacant on airplanes reduced exposure to SARS-CoV-2 by up to 57% in a laboratory-based modeling study, according to results published in MMWR.
“Physical distancing of aircraft passengers, including through policies such as middle seat vacancy, could provide additional reductions in SARS-COV-2 exposure risk,” Byron W. Jones, PhD, director of the National Gas Machinery Laboratory at Kansas State University, and colleagues wrote.
“This study could help inform future modeling of transmission risk, which might encompass determinants that were not fully explored here such as mask use, virus characteristics and host characteristics, such as vaccination status,” they wrote.
The study had three components, including a lab experiment that used bacteriophage MS2 virus as a substitute of SARS-CoV-2 to model the relationship between seating proximity on aircrafts and virus exposure.
According to the researchers, bacteriophage MS2 “has frequently been used as a surrogate for pathogenic viruses in aerosolization studies.” In their study, Jones and colleagues used it “to approximate the airborne dispersion of SARS-CoV-2” during an experiment in which mannequins were seated in a mock cabin and exposed to MS2 aerosol from different sources in the cabin.
Compared with full occupancy scenarios, the researchers observed a 23% reduction in exposure for a single passenger who was seated in the same row and two seats away from the SARS-CoV-2 source, as opposed to being seated in an adjacent middle seat. Quantified to an entire 120-passenger cabin, rather than to a single passenger, the reductions ranged from 35% to 39.4%.
In a scenario involving a three-row section with a mix of SARS-CoV-2 sources and other passengers, there was a 57% reduction in exposure with vacant middle seats, the researchers reported.
They noted several limitations of the study, including the high humidity in the laboratory and the use of spray bottles to distribute droplets.
“The extent to which exposure reduction might decrease transmission risk is not yet understood,” Jones and colleagues wrote. “Current CDC guidelines recommend against travel for persons who have not been vaccinated and require masking for all persons while on aircraft.”