Abstract
As a basic study on the development of vaccine for pseudotuberculosis in cultured yellowtail, Seriola quinqueradiata, the present paper describes our investigations into humoral aspects of immune response and efficacy of experimental vaccination against this disease in yellowtail.
The experiments indicated that the epidemics of pseudotuberculosis in the adult yellowtail were prevented by post-infectious immunity. In addition, it was observed that yellowtail immunized by intraperitoneal injection with formalin-killed cells of Pasteurella piscicida which was the causative agent of this disease, produced substantially the same agglutinating antibody as in the case of post-infectious immunity. However, only macroglobulin antibodies with agglutinating antibody activity in serum were detected.
Vaccination by oral, immersion, and spray methods that were practical for mass vaccination of fish were applied to pseudotuberculosis in yellowtail. Efficacy of vaccination by these methods were compared to the one by injection method, and the result shows that both are almost highly the same in efficacy. It was observed that agglutinating antibody was concentrated in the tissue stimulated with antigen.
