Highly Conserved Protective Epitopes on Influenza B Viruses

TLDR

Influenza A dominates pandemic discussions, yet influenza B also contributes significantly to annual flu burden, existing as two distinct lineages. The study leverages structural data from monoclonal antibodies bound to hemagglutinin, combined with known influenza A antibodies, to guide universal vaccine design against both influenza types. Three monoclonal antibodies were identified that protect mice from lethal influenza B infection; two target distinct HA regions and neutralize multiple B strains, while a third binds the HA stem and neutralizes both influenza A and B.

Abstract

Influenza Antibodies, Part B With its ability to reassort in animal hosts like pigs and birds, and to cause pandemics, influenza A viruses are often in the spotlight. However, a substantial portion of the annual flu burden is also the result of influenza B virus, which is a single influenza type that is characterized by two antigenically and genetically distinct lineages. Dreyfus et al. (p. 1343 , published online 9 August) identify three monoclonal human antibodies that are able to protect against lethal infection with both lineages of influenza B virus in mice. Two antibodies, which bind to distinct regions of the viral hemagluttinin (HA) molecule, neutralize multiple strains from both lineages of influenza B virus, whereas the third antibody binds to the stem region of HA and is able to neutralize both influenza A and B strains. The structural data from these antibodies bound to HA, together with already known antibodies targeting influenza A, may provide clues for designing a universal vaccine to protect against both influenza virus types.