Federal health officials upended the immunization schedule for American children this week. These are the diseases affected.

Here’s what to know about the dominant version of the virus that’s circulating now.

Federal officials will soon begin testing the country’s milk supply for the virus. Here’s what to know.

The health care system has stockpiles of medicine and has worked out “a lot of the kinks” since the Covid pandemic. But experts still have some concerns about a bird flu outbreak.