Citing data that people are most contagious one or two days before symptoms and up to two or three days after symptoms, the CDC says asymptomatic people who leave isolation after a five-day period should still wear a mask for another five days.
Dr. Frank Rhame, an infectious diseases physician at Abbott Northwestern Hospital and Allina Health, called the changes in guidance "dramatic."
"I think it's based on the CDC recognition that the omicron illness is not as severe, and that it's spreading so fast that we're in real danger of industries collapsing because they don't have people to staff things," Rhame said. "I think they're accepting a few extra transmissions so that things are not shut down as much as they'd be if they keep people out 10 days."