The Centers for Disease Control and Prevention revised its guidelines on Monday to say that the coronavirus can sometimes spread through airborne particles that linger in the air.
"These transmissions occurred within enclosed spaces that had inadequate ventilation," the CDC's new guidance says. "Sometimes the infected person was breathing heavily, for example while singing or exercising."
The health agency said it was much more common for COVID-19 to spread through close contact than through airborne transmission.
Some doctors are saying the term airborne is "not to be feared by the public."
"It just means you have to add some additional controls to what you're doing," said Joseph Allen, a health scientist director of Harvard University's Healthy Buildings program. "Wear a mask, keep your distance, wash your hands, and bring in a bit more outdoor air."
🔦 The guidance follows the CDC mistakenly posting guidance in September that the virus could spread beyond six feet through aerosols, or small droplets, that can linger in the air. It removed that posting at the time, saying that it was draft of proposed changes.