Comparisons of the cellular immune response of fish [rainbow trout, Salmo gairdneri] vaccinated by immersion and injection of Vibrio anguillarum

The cellular immune response of rainbow trout Salmo gairdneri immunized by immersion or injection with Vibrio anguillarum bacterin was investigated using the passive antibody producing cell assay and passive antibody rosette-forming cell assay. The hemagglutinating antibody of the serum against V. anguillarum of fish vaccinated by immersion tended to be as low as the serum of non-vaccinated fish. However, the hemagglutinating antibody in fish vaccinated by injection was detected first on the 13th day after immunization. The maximum value of the titer was reached on the 28th day after immunization.