Nasal delivery of H5N1 avian influenza vaccine formulated with GenJet™ or in vivo-jetPEI® induces enhanced serological, cellular and protective immune responses

AbstractAvian influenza virus infection is a serious public health threat and preventive vaccination is the most cost-effective public health interventionstrategy. Unfortunately, currently available unadjuvanted avian influenza vaccinesare poorly immunogenicand alternative vaccine formulations and delivery strategies are in urgent need to reduce the high risk of avian influenza pandemics. Cationic polymers have been widely used as vectors for gene deliveryin vitro and in vivo. In this study, we formulated H5N1 influenza vaccineswith GenJet™ or in vivo-jetPEI®, and showed that these formulations significantly enhanced the immunogenicityof H5N1 vaccinesand conferred protective immunity in a mouse model. Detailed analyses of adaptive immune responses revealed that both formulations induced mixed TH1/TH2 antigen-specific CD4 T-cell responses, antigen-specific cytotoxic CD8 T-cell and memory B-cellresponses. Our findings suggest that cationic polymers merit future development as potential adjuvants for...