What is H5N9 and how is it different from H5N1? Scientists classify bird flu viruses by which kind of two key proteins are inside of them: the hemagglutinin, like H5 or H3, and th

Bird flu cases are still rising in the U.S. as the virus continues to devastate poultry farms. More than 145 million chickens, ducks, turkeys and other fowl have been slaughtered across the United States since the outbreak began in January 2022. As for humans, 67 people have been infected, according to the Centers for Disease Control.