How likely is it that you will catch the flu on a fully packed airplane during flu season?

According to a new study, not very likely.

But a lot depends on who else is sitting in your row, and the row in front and in back of you. It also depends on whether you use the airplane’s bathroom, what you touch and how carefully you wash your hands.

Flu is most commonly transmitted by small respiratory droplets that move through the air when an infected person sneezes, coughs or talks. The droplets don’t go especially far — typically six feet or so — and they don’t become suspended in an aerosol that travels through currents of air in the plane’s cabin, where they could be breathed in. The flu virus can also be picked up from something an infected person touched.

For the study, the research team took five round-trip flights from Atlanta to West Coast cities, four of them during the flu season. Each of the flights had 14 researchers aboard to observe the other passengers and crew. In all, they recorded the movements of 1,540 passengers and 41 crew members. Only one passenger on one flight was seen coughing.