Elevated replication, pathogenicity, and immune evasion of Texas dairy cattle H5N1 vs. avian strain
The emergence and persistence of highly pathogenic avian influenza (HPAI) A(H5N1) viruses in terrestrial mammals, particularly dairy cattle, demand urgent attention from the scientific community and health authorities. Since the initial outbreak in March 2024, the H5N1 strain has rapidly spread across multiple U.S. states, leading to human infections primarily linked to exposure to infected cattle. A study published in Scientific Reports examines the growth properties, pathogenicity, and immune evasion mechanisms of a Texas cattle-derived H5N1 virus, comparing it to a historical avian isolate to assess the risks associated with this emerging virus.
The authors characterize an HPAI A(H5N1) isolate from a Texas dairy cow, evaluating its in vitro replication and in vivo pathogenicity relative to a classical HPAI strain (A/whooper swan/Mongolia/244/2005(H5N1) [M244/05]).
Their findings reveal that the cattle-derived H5N1 virus exhibits significantly enhanced replication kinetics in human lung cell lines and heightened pathogenicity in mouse models, resulting in severe lung pathology, high brain virus titers, and increased mortality.
