After a sharp uptick in flu cases in mid-December 2025, flu activity across the U.S. and Canada remains high.

Flu cases and hospitalizations are surging, already breaking last season's records. Here's where activity is highest, what ...

California public health officials cautioned more children are testing positive for the flu this season. Here are flu ...

Measles has been spreading in the U.S. for a year, a milestone that could mean the virus can no longer be considered ...