A contagious new COVID-19 variant called NB.1.8.1, aka "Nimbus," is now dominant in the United States, CDC data show. What to know about symptoms and vaccines.

A federal judge in New Hampshire said he'll certify a class action lawsuit including all children who'll be affected by ...

The U.S. is having its worst year for measles spread in more than three decades, with a total of 1,288 cases nationally and ...