Here’s how coronavirus spreads on a plane—and the safest place to sit

When an outbreak strikes, it is natural to become leery of hopping on an airplane. It is even more alarming when two serious viruses are circulating at once.

The world is gripped by a new coronavirus that started in China and has since movedinto more than 85 countries, including the United States. Meanwhile, it is also flu season, which so far has caused 18,000 deaths in the U.S.

Major airports have begun screening passengers for the coronavirus, and more than three dozen airlines—including Delta, American, and United—have cut their flights to China and other places affected by the crisis. But those measures may not provide much solace to anyone who has to board a flight.

After all, you can avoid the person who is sneezing in line at Cinnabon, but you’re more or less left to fate once you’ve strapped on that seatbelt inside a flying metal canister.

While there is still much to learn about the Wuhan outbreak, scientists do know a bit about similar coronaviruses and other respiratory illnesses like influenza. So how do those viruses spread—and specifically on airplanes? And how serious is the coronavirus threat compared to the likes of influenza? Let’s take a look.

How do respiratory illnesses spread in general?

If you’ve ever sneezed into your arm or steered clear of an office colleague with a hacking cough, you already know the basics of how respiratory illnesses spread.

When an infected person coughs or sneezes, they shed droplets of saliva, mucus, or other bodily...