Vaccination is one of the most important and effective methods of prevention and control of infectious diseases. Infectious hematopoietic necrosis disease (IHN) is one of the most important viral diseases of salmonids, especially rainbow trout, which in recent years has caused severe damage to rearing farms of trout fish. To overcome this disease, a recombinant vaccine for infectious hematopoietic necrosis virus (RIBB-IHNV) has been produced in the Research Institute of Biotechnology and Bioengineering of Isfahan University of Technology. The aim of this study was to trace the presence of infectious necrosis virus (IHNV) vaccine in different tissues of rainbow trout. For this purpose, broodstocks weighing approximately 900 g to 1200 g were divided into 5 experimental treatments (including the control group, 0.01, 0.1, 1 and 10 micrograms of vaccine per 5 g of fish weight) and their serum was eva‎luated in serum neutralization test (NA) at 1, 4 and 9 months post-vaccination. After sexual maturation, the broodstocks were artificially inseminated to produce fertile eggs and larvae. Then, the survival and persistence of the vaccine in different tissues of broodstocks and their larvae were determined by the amplification of vaccine glycoprotein (G) gene in polymerase chain reaction (PCR) and tracking of its mRNA expression by reverse transcription PCR (RT-PCR). Also, in order to eva‎luate the possibility of immune transmission from parents to offspring, larvae from broodstocks were challenged with IHNV and at the end of 30 days, their relative survival rate and cumulative mortality rate were calculated. Based on the results at 2, 4 and 8 weeks after hatching, neither G gene amplification in PCR nor its expression in RT-PCR was observed in different tissues. Furthermore, examination of vaccinated broodstocks tissues (liver, spleen, heart, pyloric appendages, muscle, gonads) did not show any sign of the presence of the vaccine. The results of exposure of fish larvae to IHNV virus showed that the vaccine in different treatments increased the relative survival rate and decreased the cumulative mortality rate compared to the control group. According on the serum neutralization test of broodstocks and their egg yolk, RIBB-IHN vaccine in different concentrations and different months after vaccination can induce immune response by producing neutralizing antibody against IHNV. In general, the results of this study indicate that the vaccine does not persist in the tissues of broodstocks and their larvae, while the vaccine-induced immunity can be transferred from parents to the next generation.

امير حسين جلالي، عيسي ابراهيمي

فاطمه پيكان حيرتي، اميد بيرقدار كشكولي