Influenza A virus hemagglutinin H7 (None)

Influenza A virus hemagglutinin (HA) is the most abundant glycoprotein on the surface of influenza virions and plays a central role in viral entry into host cells. The H7 subtype refers to one of several antigenically distinct forms of HA found in influenza A viruses, with particular relevance for avian and zoonotic infections. HA binds sialic acid-containing receptors on vertebrate cell surfaces via its HA1 domain, enabling viral attachment and subsequent endocytosis. Acidification within endosomes triggers conformational changes in HA, and the fusion peptide (part of HA2) inserts into the endosomal membrane, facilitating fusion between viral and cellular membranes—releasing viral RNA into the cytoplasm for replication. As a major antigenic determinant, HA is the target of neutralizing antibodies; antigenic drift and shift can compromise immunity. H7 strains are primarily associated with avian hosts but have caused human infections.

Other names

H7 HemagglutininHA H7H7 HA

Attachment to host cell receptors and membrane fusion