Hemagglutinin of Influenza A (HA)

Hemagglutinin of Influenza A is a trimeric, surface-exposed viral glycoprotein crucial for the infectivity of influenza A viruses. It mediates viral attachment to host cells via specific recognition of sialic acid residues and catalyzes fusion of the viral envelope with the host endosomal membrane following endocytosis. Hemagglutinin is the primary target of neutralizing antibodies and underlies most antigenic variation—through antigenic drift and shift—that leads to seasonal epidemics and pandemics. At least 18 HA subtypes are known, with H1, H2, and H3 infecting humans, and other subtypes circulating in avian and mammalian reservoirs. The protein is the major immunogen for vaccine design and a key target for both prophylactic and therapeutic intervention against influenza[1][2][5][9][10].

Other names

Influenza A hemagglutininHA proteinInfluenza hemagglutininH antigen

Blockade of receptor binding - Inhibition of membrane fusion - Neutralization via antibody recognition of conserved regions