H5N1 Found in Dairy Cattle Retains Preference for Infecting Birds, Representing Low Risk to Humans

Avian influenza virus from the ongoing outbreak in dairy cattle appears to be keeping its bird-infecting features rather than adapting to better infect other mammals, according to a new study from St. Jude Children’s Research Hospital. Since 2024, when scientists first detected H5N1 bird flu in dairy cattle, they have worried that the virus would use the animals as a bridge to mutate and gain the ability to better infect and spread in humans. The St. Jude researchers tested a panel of these viruses from dairy cows, finding they had more molecular and biological features in common with avian than human flu viruses.