An inactivated multivalent influenza A virus vaccine is broadly protective in mice and ferrets [mouse]

Influenza A viruses (IAVs) present major public health threats from annual seasonal epidemics and pandemics as well as from viruses adapted to a variety of animals including poultry, pigs, and horses. Vaccines that broadly protect against all such IAVs, so-called “universal” influenza vaccines, do not currently exist, but are urgently needed. Here, we demonstrated that an inactivated, multivalent whole virus vaccine, delivered intramuscularly or intranasally, was broadly protective against challenges with multiple IAV hemagglutinin and neuraminidase subtypes in both mice and ferrets. The vaccine is comprised of four beta-propiolactone-inactivated low pathogenicity avian influenza A virus subtypes of H1N9, H3N8, H5N1, or H7N3. Vaccinated mice and ferrets demonstrated substantial protection against a variety of IAVs, including the 1918 H1N1 strain, the highly pathogenic avian H5N8 strain, and H7N9. We also observed protection against challenge with antigenically variable and heterosubtypic avian, swine, and human viruses. Compared to mock vaccinated animals, vaccinated mice and ferrets demonstrated marked reductions in viral titers, lung pathology, and host inflammatory responses. This vaccine approach indicates the feasibility of eliciting broad, heterosubtypic IAV protection and identifies a promising candidate for influenza vaccine clinical development. Lung gene expression profiles from vaccinated or non-vaccinated mice and ferrets challenged with different influenza viruses were compared to lung tissue from unvaccinated, uninfected control animals.