For millions of years, various types of coronavirus have thrived in hundreds of bat species without causing any harm. But when they’ve occasionally jumped to humans—as was the case with SARS in 2003 and SARS-CoV-2 last year—they caused havoc, suggesting that at least some people’s immune systems lack antiviral defences present in bats.
Scientists are now looking to genomes of bats for clues about how these animals fight off coronaviruses. “We could potentially take what we learn from bats and apply it to humans,” says Erich Jarvis, a professor at The Rockefeller University. For example, he hopes that this