Genetic Diversity, Reassortment Patterns, and Antigenic Characterization of Two H9N2 Avian Influenza Viruses Isolated from Quails in China
H9N2 avian influenza viruses pose a persistent zoonotic risk owing to their broad host adaptability. Between 2024 and 2025, two H9N2 isolates (ZHY1022B2 and ZHY0417A11) were recovered from quail flocks in Hebei, China. Phylogenetic analysis clustered their HA genes within the dominant B4.7.2 subclade, but diverged into...