About Influenza B Hemagglutinin (HA) (B/Austria/1359417/2021, Victoria Lineage) Recombinant Protein

Influenza B virus is a major cause of seasonal influenza epidemics and contributes substantially to annual respiratory illness worldwide. Unlike influenza A viruses, influenza B viruses circulate almost exclusively in humans and are classified into two antigenically distinct lineages: Victoria and Yamagata. The B/Austria/1359417/2021 (Victoria lineage) strain was selected by the World Health Organization (WHO) as a recommended vaccine strain for recent seasonal influenza vaccines because of its antigenic properties and global circulation.

The viral hemagglutinin (HA) glycoprotein is the major surface antigen of influenza B virus and mediates attachment to sialic acid-containing receptors on host epithelial cells, followed by receptor-mediated endocytosis and membrane fusion. As the principal target of neutralizing antibodies, HA is the primary antigen used in influenza vaccines and an essential reagent for studies of viral entry, antigenicity, and immune responses. eEnzyme's Influenza B Hemagglutinin (HA) (B/Austria/1359417/2021, Victoria Lineage) Recombinant Protein is expressed in HEK293 cells, providing native mammalian glycosylation and proper protein folding. The purified recombinant HA is suitable for ELISA, Western blotting, antibody characterization, vaccine research, receptor-binding studies, structural biology, and diagnostic assay development.

Applications

Biological Significance of Influenza B Hemagglutinin

Hemagglutinin is the key viral glycoprotein responsible for initiating influenza infection by binding terminal sialic acid receptors on host cells and mediating low pH-induced membrane fusion within endosomes. Because HA is exposed on the viral surface, it is the dominant target of protective humoral immunity and the primary antigen incorporated into seasonal influenza vaccines. Continuous antigenic drift within HA drives the emergence of new influenza variants and necessitates periodic vaccine updates. The B/Austria/1359417/2021 (Victoria lineage) strain contains characteristic antigenic changes that distinguish it from earlier B/Victoria viruses and has therefore become an important reference strain for vaccine potency testing, antigenic surveillance, and influenza research.

The Influenza B Hemagglutinin (HA) (B/Austria/1359417/2021, Victoria Lineage) Recombinant Protein provides a valuable research tool for investigating influenza virus biology, evaluating vaccine-induced immune responses, screening therapeutic antibodies, and supporting the development of next-generation influenza vaccines and antiviral therapeutics.