With so much H5N1 circulating in the U.S., scientists worry we are a few mutations away from a potential human pandemic.

Bird flu infects many species, including wild animals, according to the United Nations. Ducks, quail and at least one eagle have been euthanized due to the virus. A global outbreak of H5 bird flu has infected millions of animals since 2020. The virus can infect chickens, cows and, more rarely, humans.

H5N1 bird flu is branching out. New data from the Centers for Disease Control and Prevention indicates that a second type of H5N1 has likely spread from dairy cows to humans.