Influenza A virus hemagglutinin H2 (H2 HA) (H2 HA)

Influenza A H2 hemagglutinin is a critical surface glycoprotein found on the H2 subtype of the Influenza A virus, most notably responsible for the 1957 "Asian Flu" pandemic (NCBI, 2023). It functions as a class I fusion protein, mediating both the initial attachment of the virus to host cell sialic acid receptors and the subsequent fusion of the viral and endosomal membranes (UniProt, 2024). The protein exists as a homotrimer, with each monomer composed of two disulfide-linked subunits, HA1 and HA2, which are generated by the proteolytic cleavage of a precursor (PubMed, 2022). Because H2N2 viruses ceased circulating in humans in 1968, a large portion of the current global population lacks immunity, making H2 hemagglutinin a high-priority target for pandemic preparedness and the development of "universal" influenza vaccines (NIH, 2023). Therapeutic interventions often focus on monoclonal antibodies that bind to the highly conserved stem region of the HA molecule, thereby blocking the conformational changes necessary for membrane fusion (Nature Communications, 2021).

Other names

HAH2Hemagglutinin subtype 2H2N2 HemagglutininInfluenza A virus H2N2 hemagglutinin

Inhibition of viral attachment to host sialic acid receptors and blockade of pH-dependent membrane fusion (Nature, 2022).