Like most people, I’ve been exposed to COVID-19 many times that I’m aware of, and surely countless other times that I’m not. Sometimes it seems like there’s no rhyme or reason to when these exposures actually get me sick. How could I have stayed healthy after driving in a car or eating lunch with a friend who didn’t yet realize they had COVID-19?

A new study offers a possible reason: it sometimes takes much longer than you think to catch the virus. Using data from a U.K. COVID-19 tracking app, the researchers found that exposures that last an hour or longer cause many more infections than shorter ones. In some cases, they found, it can take more than a full day for the virus to jump from one person to another.

This doesn’t mean it’s impossible to catch COVID-19 when you’re out running errands or commuting to work. But, the researchers told me, people should remember that places where they spend the most time around others—like their home or workplace—may be where the virus is most likely to spread.

READ THE REST