Hemagglutinin (Influenza B virus Yamagata-lineage) (HA) (HA)

The Influenza B/Yamagata-lineage hemagglutinin (HA) glycoprotein is a critical surface protein of the Influenza B virus responsible for viral entry into host cells. It functions by binding to terminal sialic acid residues on host cell surface glycoproteins and glycolipids, followed by mediating the fusion of the viral envelope with the endosomal membrane after endocytosis (UniProt: P03460). As the primary antigen recognized by the host immune system, HA is the principal component of seasonal influenza vaccines designed to elicit neutralizing antibodies (CDC, 2023). The Yamagata lineage, along with the Victoria lineage, has historically been a major cause of seasonal respiratory illness worldwide. However, due to the lack of detected Yamagata lineage viruses in global surveillance since March 2020, the World Health Organization (WHO) has recently recommended its removal from future vaccine formulations (WHO, 2024). Despite this, HA remains a primary target for the development of universal influenza vaccines and novel entry inhibitors (PubMed: 32733060).

Other names

Influenza B Yamagata HAHemagglutinin glycoproteinB/Yamagata/16/1988-like HAInfluenza B virus (B/Yamagata/16/1988) hemagglutininHA1 subunitHA2 subunit

Binding and neutralization of the hemagglutinin protein to prevent viral attachment to host cell sialic acid receptors and inhibit subsequent membrane fusion.