A single mutation in the H5N1 strain of avian influenza that is infecting cattle in the US could make it more likely to infect humans, according to a new scientific paper.

The person was over the age of 65 and had underlying medical conditions. They were hospitalized last month with the U.S.'s first severe bird flu case.

The current H5N1 outbreak began in 2022 and intensified throughout the Biden administration. By early 2025, the virus had affected over 130 million birds, including both wild and domestic populations.

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.