A 13-year-old girl in Canada became so sick with H5N1, or bird flu, in late 2024 that she had to be put on a ventilator. Around the same time, a senior in Louisiana was diagnosed with the first "severe" case in the U.S.

Stanford University researchers have developed a way to make the seasonal flu vaccine stronger against more strains, potentially including those that cause bird flu, the university said this month.  By stitching together four molecules found in the standard vaccine,