H5N1 virus from 2022 mink outbreak capable of inefficient airborne transmission

Highly pathogenic H5N1 avian influenza was detected in dairy cattle for the first time in the United States in March, with nine states reporting outbreaks by May. While the method of transmission among cattle is currently unknown, new research demonstrates that a related strain of H5N1, subtype clade 2.3.4.4b, which caused an outbreak in farmed mink in 2022, transmitted through the air to a limited number of ferrets. This is the first time that a member of the group of H5N1 clade 2.3.4.4b viruses has been shown to exhibit this ability. According to the researchers, the findings suggest these viruses are evolving to infect mammals and with potentially increased risk to humans.