DEVELOPMENT OF AN ADULT SALMONID INJECTION IMMUNIZATION PROCEDURE AGAINST IHN VIRUS

INFECTIOUS HEMATOPOIETIC NECROSIS (IHN) IS A HIGHLY INFECTIOUS RHABDOVIRAL DISEASE OF IMPORTANT SPECIES OF TROUT AND SALMON, BOTH CULTURED COMMERCIALLY AND AS PART OF FEDERAL AND STATE SPORT FISHERIES AND ENHANCEMENT PROGRAMS. THERE ARE PRESENTLY NO PROVEN OR ACCEPTED METHODS FOR PREVENTION OR TREATMENT OF IHN OR IHN VIRUS (IHNV) CARRIES. UNDER THE INTENSIVE CULTURE CONDITIONS OF AQUACULTURE, IHNV CAN CAUSE SIGNIFICANT LOSSES AT NEARLY ALL STAGES OF SALMONID PRODUCTION. ADDITIONALLY, ADULT SALMONIDS THAT CARRY IHNV POSE THREATS OF EGG-ASSOCIATED TRANSMISSION OF VIRUS AND AS A RESERVOIR OF INFECTION VIRUS THAT COULD CONTAMINATE SUSCEPTIBLE JUVENILES. SUCCESSUFL VACCINATION AGAINS IHNV MIGHT SIGNIFICANLTY REDUCE MORTALITY AND OTHER DISEASE PROBLEMS ASSOCIATED WITH VIRAL INFECTION. VACCINATION BY INJECTION IS SIGNIFICANTLY MORE EFFECTIVE AT ELICITING A PROTECTIVE RESPONSE COMPARED TO IMMERSION DELIVERY IN FISH. THUIS INJECTION VACCINATION AGAINST IHNV COULD PROVIDE A SOLUTION TO THE IHNV PROBLEM BY ELICITING IHNV NEUTRALIZING ANTIBODIES THAT HAVE ALREADY BEEN SHOWN TO BE PROTECTIVE. THREE TYPES OF IHNV VACCINES ARE CURRENTLY UNDER DEVELOPMENT INCLUDING MODIFIED-LIVE (ATTENUATED) AND KILLED VIRUSES, AND A SUBUNIT VACCINE PRODUCED BY RECOMBINANT DNA TECHNOLOGY. EACH VACCINE WILL BE EVALUATED AFTER INJECTIIN DELIVERY IN TWO YEAR OLD RANBOW TROUT FOR INDUCTION AND KINETICS OF IHNV NEUTRALIZING ANTIBODIES AT TWO IMMONOGEN CONCENTRATIONS.