There’s increasing emphasis on wearing masks while flying. How much protection do they offer against COVID-19?

SYDNEY, AUSTRALIA – SEPTEMBER 24: Passengers and crew onboard a Qantas Boeing 737-800, flight number QF735 from Sydney to Adelaide at Sydney Airport on September 24, 2020 in Sydney, Australia. Flights from Sydney to Adelaide have resumed after the South Australian government’s decision to lift COVID-19 travel restrictions for NSW residents. From Thursday 24 September, travellers from New South Wales are able to enter South Australia without having to go into a mandatory 14-day quarantine. (Photo by James D. Morgan/Getty Images)