Featured in Omicron
What to do if you test positive for COVID, were exposed, or have symptoms
Here's why the CDC changed its guidelines.
Omicron isn’t overtaking Delta as quickly as the CDC thought—and that’s bad news
Omicron is not infecting people at the rate officials thought.
Why the CDC just shortened COVID quarantines to 5 days for asymptomatic cases
This change reflects when people are most likely to transmit the coronavirus, the agency says.
New study finds booster protection against Omicron drops at 10 weeks
Protection against severe disease and hospitalization, however, should last much longer.
It’s too early to dismiss Omicron as a mild COVID variant
With more people vaccinated, estimating Omicron's severity is an incredibly difficult task.
Researchers are racing to figure out if Omicron can beat our vaccines
Research on the immune system response to Omicron gives us clues about vaccine efficacy. Here's what it can tell us, and what it can't.