Hemagglutinin of Influenza B virus, Victoria lineage (HA (Victoria lineage))

Hemagglutinin of the Victoria lineage is a major surface glycoprotein of Influenza B virus responsible for binding to sialic acid–containing receptors on host cells, initiating viral attachment and membrane fusion required for infection[6][2][3]. It is the primary target of neutralizing antibodies, making it a key antigen in seasonal influenza vaccines and a focus of therapeutic antibody development[5]. The Victoria lineage is one of two main evolutionary branches (along with Yamagata) of Influenza B virus hemagglutinin, differentiated by genetic and antigenic properties. HA functions as a trimer that undergoes proteolytic cleavage and acid-triggered conformational changes necessary for membrane fusion and viral entry into the host cell[3][2]. Antigenic drift in HA leads to regular updates in vaccine composition due to immune escape and poses ongoing challenges for influenza control.

Other names

Hemagglutinin (HA) of Influenza B virus Victoria lineageB/Victoria lineage hemagglutininInfluenza B Victoria HA

Antibodies (from infection, vaccination, or therapy) neutralize virus by blocking HA’s binding to host receptors or inhibiting fusion mechanism[5]