Fc-Effector-Independent in vivo Activity of a Potent Influenza B Neuraminidase Broadly Neutralizing Antibody

Influenza B virus (IBV) contributes to substantial influenza-mediated morbidity and mortality, particularly among children. Similar influenza A viruses (IAV), the hemagglutinin (HA) neuraminidase (NA) of IBV undergo antigenic drift, necessitating regular reformulation seasonal vaccines. NA inhibitors, such as oseltamivir, have reduced activity clinical efficacy against IBV, while M2 channel inhibitors are only effective IAV, highlighting need for improved vaccine therapeutics treatment infections. We previously described a potent human monoclonal antibody (hMAb), 1092D4, that is specific neutralizes broad range IBVs. The anti-viral MAbs can include direct mechanisms through neutralization and/or Fc-mediated effector functions dependent on accessory cells expressing Fc receptors could be impacted by potential host-dependent variability. To discern if in vivo 1092D4 was Fc-effector function, hMAb with ability bind (1092D4–LALAPG) generated tested. 1092D4–LALAPG had comparable vitro binding, neutralization, inhibition 1092D4. at protecting lethal challenge mice. These results suggest minimally functions, characteristic may extend other hMAbs activity.