Keeping middle seats free could give airline passengers more protection from Covid-19, a new study suggests.
Researchers said the risk of passengers being exposed to the virus from an infected person could be reduced by 23 per cent to 57 per cent if middle seats are empty, compared with a full flight.
The study supports the response of airlines that limited seating early in the pandemic. But most airlines have now stopped blocking middle seats with US carrier Delta one of the last to start selling them again.
Carriers argue that filters and air-flow systems on most planes make them safe when passengers wear face masks.
Researchers at the US Centres for Disease Control and Prevention (CDC) and Kansas State University estimated how far airborne virus particles travel inside a plane. They used mannequins that emitted aerosol to measure the flow of virus particles through airline cabin mock-ups.
The study, however, did not take into account the wearing of face masks because it was based on a previous study done in 2017, before the pandemic and nor did it consider whether passengers are vaccinated against Covid-19.
The CDC says vaccinated people can travel at low risk to themselves, although the agency still recommends against non-essential travel.
Airlines for America, a trade group for the largest US carriers, said airlines use several layers of measures to prevent the spread of the virus on planes, including face masks, asking passengers about their health, and stepped-up cleaning of cabins.
A Harvard University report funded by the airline industry shows the risk of transmitting the coronavirus on planes is very low.