VIBRIO ANTIGENS OF POLYVALENT VACCINES ENHANCE THE HUMORAL IMMUNE-RESPONSE TO AEROMONAS-SALMONICIDA ANTIGENS IN ATLANTIC SALMON (SALMO-SALAR L)

Seven experimental oil-adjuvanted vaccines containing Aeromonas salmon icida and one or more of the following components: Vibrio salmonicida, Vibrio anguillarum serovar O1 and V. anguillarum serovar O2, were com pared to a monovalent A. salmonicida vaccine regarding their ability t o induce antibody production against A. salmonicida in Atlantic salmon . Enzyme-linked immunosorbent assay (ELISA) tests were used to measure the humoral immune response against various antigen preparations from A. salmonicida; bacterial cell-sonicate, A-layer protein and lipopoly saccharide. The effects of the different Vibrio spp, on the generation of specific antibodies were estimated through a factorial statistical design. The results showed that stronger humoral immune responses to A. salmonicida antigens were induced in fish vaccinated with the vario us polyvalent vaccines, compared to fish vaccinated with the monovalen t furunculosis vaccine. V. salmonicida tended to be the most important component for this enhancement, although V. anguillarum also contribu ted. Immunological cross-reactions between A. salmonicida and V. salmo nicida is a possible mechanism. (C) 1997 Academic Press Limited.