Identification of Immunogenic Components of Flavobacterium Psychrophilum for a CWD Vaccine

Coldwater disease (CWD), caused by Flavobacterium psychrophilum, results in severe losses to salmonid aquaculture worldwide. In recent years, this disease has had a significant economic impact on commercial, Federal and State aquaculture facilities in the U.S. Immunization against this disease would provide the most benefit to producers, and although significant protection has been observed under laboratory conditions, no commercial vaccines exist. This is likely due to virulence differences observed among F. psychrophilum isolates. This Phase I study will evaluate and identify immunogenic antigens of F. psychrophilum and determine the role of virulence-associated proteins in conferring antibody- mediated protection. Limited data exists on the immune response of fish to F. psychrophilum, but is considered essential to developing a vaccine to CWD. Therefore, this study will 1) evaluate antibody responses to F. psychrophilum following immunization via injection and immersion routes, 2) identify the major bacterial protein components to which an antibody response is generated, and 3) determine the importance of these antigens in protection from pathogen challenge. This will greatly increase our understanding of the immune response to this disease and provide a foundation for the development of vaccine in Phase II studies that would greatly benefit the aquaculture industry.