When, where and how the H5N1 bird flu virus may evolve and its capacity to spark a pandemic is hard to predict — in part, some researchers say, because of federal restrictions on gain-of-function research.

The CDC has declared the first “severe” case of H5N1 bird flu in the U.S., according to a press release published Wednesday. The good news? The person who contracted the virus appears to have gotten it from backyard poultry,

Mississippi has confirmed H5N1 in a poultry flock. The birds are not part of food supply chain. What you need to know about bird flu symptoms, risk.