Protection Against H7 Subtype Influenza Virus Infection in Mice by Passive Transfer of Neutralizing Monoclonal Antibody.

H7 subtype influenza viruses pose serious threats to both the poultry industry and public health. Recent human infections of avian H7N9 influenza viruses with substantial morbidity and mortality have raised concerns about this virus becoming a potential pandemic pathogen. Neutralizing antibodies have been proven to be highly effective in blocking influenza virus infections. In this study, in order to develop an antibody-based immunoprophylaxis against H7 subtype influenza virus, we first generated a neutralizing monoclonal antibody (MAb) by using a pseudotyped lentiviral vector carrying the hemagglutinin protein of H7 subtype influenza virus. In vitro studies demonstrated that this neutralizing MAb completely inhibited the infection of an H7 subtype influenza virus to cells. The protective efficacy of this MAb was then further tested in a mouse model. It was shown that passive immunization of this MAb protected mice from local virus challenge. Results of the current study lay a foundation for the development of neutralizing MAb-mediated prophylactic strategies to combat human H7 influenza virus infections.