2025/26 subclade-specific influenza A and B vaccine effectiveness estimates and discordant laboratory-based indicators of vaccine match or mismatch
Background: The 2025/26 influenza season included A(H3N2) subclade K predominance with A(H1N1)pdm09 co-circulation and subsequent prolonged influenza B activity. The Canadian Sentinel Practitioner Surveillance Network reports vaccine effectiveness (VE) in the context of genetic and antigenic relatedness to circulating...