Highly pathogenic avian influenza H5N1 in the United States: recent incursions and spillover to cattle

Since Spring 2024, new genotypes of highly pathogenic avian influenza (HPAI) H5N1 clade 2.3.4.4b have been identified in the United States (US). These HPAI H5N1 genotypes have caused unprecedented multi-state outbreaks in poultry and dairy farms, and human infections. Here, we discuss the current situation of this outbreak and emphasizes the need for pre-pandemic preparedness to control HPAI H5N1 in both poultry and dairy farms in the US.