Influenza B virus Victoria lineage hemagglutinin protein (HA (Hemagglutinin))

The Influenza B virus Victoria lineage hemagglutinin protein is a trimeric surface glycoprotein essential for the infectivity of influenza B viruses. It mediates attachment to sialic acid-containing receptors on the surface of respiratory epithelial cells, initiating endocytosis. Upon exposure to acidic pH within the endosome, it undergoes conformational changes that drive fusion between the viral envelope and host cell membrane, allowing release of the viral genome into the cytoplasm. The globular head domain contains highly variable antigenic sites responsible for immune recognition, while a more conserved stem region houses the fusion machinery. Hemagglutinin is a major target for neutralizing antibodies elicited by natural infection or vaccination; thus, it is central to both seasonal flu vaccine design and therapeutic antibody development. The Victoria lineage represents one of two main evolutionary branches ("lineages") circulating globally since their divergence several decades ago[1][2][3].

Other names

HemagglutininHAInfluenza B-Victoria hemagglutininInfluenza B virus hemagglutinin (Victoria lineage)

Drugs or antibodies targeting this molecule block receptor binding or prevent conformational changes required for membrane fusion, thereby inhibiting viral entry into host cells[1].