Project Abstract This interdisciplinary proposal brings together three highly successful but independent technologies to create an effective and broadly neutralizing universal influenza vaccine. Our approach combines breath of immunity, by using a consensus HA strategy, production speed and capacity by working with Kentucky BioProcessing (KBP), who can express HA protein in plants, and vastly improved subunit vaccine potency using a TMV-HA conjugation approach to create a candidate universal influenza virus vaccine. Based on our preclinical data on three influenza A strains, we expect our approach will drive long term immunity that is balanced between antibody and cellular immunity, providing potential for overlapping mechanisms of immune protection. We bring together a strong team of different disciplines with a combined goal to quickly show proof of concept with H1, H3, H5, and M2e antigens. Our Specific Aims are as follows: 1) Production of TMV-HA conjugates of centralized H1, H3, H5 genes and M2e peptide, 2) Immune response analysis, murine challenge studies and 3) Translational and ferret studies of TMV-HAc and TMV-M2e vaccines. Dr. Weaver has developed a computational method to express an ancestral sequence of HA, representing a consensus of sequences within an Influenza subtype. These vaccines protect against drifted seasonal influenza variants better than a traditional trivalent inactivated virus vaccine. In partnership with KBP, we will use established plant expression methods to produce centralized HA proteins, with the capacity to produce protein for the planned studies and for future clinical trial development. HA consensus protein will be fused to the surface of Tobacco Mosaic virus (TMV) by chemical conjugation, a method developed by Dr. McCormick to improve HA subunit vaccine potency. TMV-HA vaccines will also be combined with a highly conserved M2e peptide vaccine, to broaden protection and reduce vaccine dose. Immunological analysis will be used to confirm vaccine potency, in order to optimize dose, schedule and route of administration. Vaccine efficacy and broadly protective immunity will be confirmed by lethal influenza challenge using 9 divergent virus types in a murine model of disease. Finally, vaccine formulations will be re-tested in ferrets, a models of influenza infection which more closely mimics the progress of disease in humans. Our vaccine is designed to drive local and systemic immunity after either intranasal or intramuscular routes of administration, and we will use immunogenicity and pathogen challenge data to define an optimized single dose vaccine formulation. Our goal is to generate an effective universal vaccine against influenza that can be manufactured at scale, with significant potential for translation into a universal vaccine product that is ready for clinical testing.