SWINE INFLUENZA VIRUS (SIV) IS ONE OF THE TOP RESPIRATORY INFECTIONS IN SWINE CAUSING SIGNIFICANT ECONOMIC LOSSES TO THE SWINE INDUSTRY EVERY YEAR. THE HIGH GENETIC DIVERSITY OF SIV AND THE CONSTANT EMERGENCE OF VARIANT VIRUSES THAT ARE ABLE TO ESCAPE IMMUNITY POSE SIGNIFICANT CHALLENGES TO VACCINE DEVELOPMENT. RECENTLY, STRATEGIES AIMING AT DEVELOPING BROADLY PROTECTIVE VACCINE CANDIDATES FOR HUMAN AND AVIAN INFLUENZA VIRUSESHAVE SHOWN PROMISSE. IN THE PRESENT PROJECT WE WILL ASSESS THE FESIBILITY AND EFFICACY OF TWO OF THESE STRATEGIES INVOLVING CONSENSUS AND CHIMERIC HA SEQUENCES AGAINST SWINE INFLUENZA. INITIALLY, WE WILL PERFORM A COMPARISON OF CONSENSUS HA VS CHIMERIC HA IN PIGS TO IDENTIFY WHICH PLATFORM HAS A BETTER CHANCE OF SUCCESS AGAINST SIV. THIS WILL BE FOLLOWED BY A FULL CHARACTERIZATION OF THE BEST PLATFORM, IN COMPARISON WITH A CURRENT WHOLE VIRUS INACTIVATED COMMERCIAL SIV VACCINE. WE EXPECT THAT THESE STUDIES WILL ALLOW US TO DETERMINE WHETHER THE CONSENSUS AND/OR CHIMERIC STRATEGIES WORK IN SWINE AGAINST SIV. ADDITIONALLY, WITH THE PROPOSED STUDIES WE EXPECT TO CHARACTERIZE IMMUNE RESPONSES THAT CORRELATE WITH CROSS-PROTECTIVE RESPONSES TO SIV IN PIGS.