New versions of the H5N1 virus are increasingly adept at spreading. Suggestions to either let it rip in poultry or vaccinate the birds could backfire.

The U.S. Centers for Disease Control and Prevention (CDC) announced the end of the bird flu emergency, at least for now.

Three ducks at the Queens Zoo have died of bird flu and 12 other birds that died at the Bronx Zoo may have come into contact with the virus, according to the Wildlife Conservation Society.