Influenza A and B conserved viral epitopes

Influenza A and B conserved viral epitopes are highly stable regions of viral proteins that serve as the primary targets for universal influenza vaccines and broadly neutralizing antibodies (bnAbs). These epitopes are primarily located within the stem (stalk) region of hemagglutinin (HA), the ectodomain of matrix protein 2 (M2e), the active site of neuraminidase (NA), and the internal nucleoprotein (NP) (Krammer, F., 2019, Nature Reviews Immunology). While the head of the HA protein undergoes rapid antigenic drift, these conserved regions are essential for viral fitness, facilitating critical functions such as membrane fusion, ion channel activity, and viral RNA packaging (Erbelding, E. J., et al., 2018, Journal of Infectious Diseases). In the context of disease, these epitopes are the focus of efforts to provide universal protection against diverse seasonal and pandemic influenza strains by overcoming the limitations of strain-specific immunity. Therapeutic strategies involve using bnAbs to block viral entry or vaccines to elicit potent B-cell and T-cell responses against these subdominant but cross-reactive sites (Corti, D., & Lanzavecchia, A., 2013, Annual Review of Immunology). Successful targeting of these epitopes aims to eliminate the need for annual vaccine reformulations and provide a robust defense against emerging zoonotic influenza threats (Impagliazzo, A., et al., 2015, Science).

Other names

Universal influenza vaccine targetsBroadly neutralizing influenza epitopesConserved influenza antigensHemagglutinin stem epitopesM2e epitopesInfluenza nucleoprotein conserved regions

Neutralization of viral entry by blocking hemagglutinin-mediated membrane fusion, inhibition of viral progeny release, and induction of antibody-dependent cellular cytotoxicity (ADCC) or T-cell mediated lysis of infected cells.