The CDC now says the coronavirus can spread farther than six feet through the air.
In new guidance published on its website, the agency also said particles can stay in the air "for minutes or even hours," especially in poorly ventilated spaces.
As a result, it can infect others, even if the carrier has left the room.
But the agency said that type of spread is uncommon, and current social distancing guidelines are still effective.
The guidance was posted on the CDC's website last month, but the agency said it was added prematurely and removed it.