Hemagglutinin presented on the surface of Lactococcus lactis confers broad cross-clade protection against different H5N1 viruses in chickens
Abstract Background Highly pathogenic avian influenza (HPAI) H5N1 virus has the potential threat to poultry industry. Current avian influenza H5N1 vaccines for poultry are clade-specific, Therefore, there is an urgent need to develop an effective vaccine for preventing and controlling H5N1 viruses from different clades. Results Recombinant L.lactis /pNZ8148-Spax-HA was generated which influenza virus hemagglutinin (HA) protein of A/chicken/Henan/12/2004 was displayed on the surface of Lactococcus lactis ( L.lactis ) and Spax was used an anchor protein. Chickens vaccinated orally with the unadjuvanted L.lactis /pNZ8148-Spax-HA could produce significant humoral and mucosal responses, as well as the neutralizing activities against different clades of H5N1 viruses. Importantly, the unadjuvanted L.lactis /pNZ8148-Spax-HA could conferred cross-clade protection against lethal challenge with different H5N1 viruses in the chicken model. Conclusion This study provides insight into the cross-clade protection conferred by the unadjuvanted L.lactis /pNZ8148-Spax-HA that may help establish a promising platform for the development of a safe and effective H5N1 cross-clade vaccine in poultry. Keywords: L.lactis /pNZ8148-Spax-HA, cross protection, H5N1 cross-clade vaccine.