Immunological findings in shrimp Litopenaeus vannamei exposed to attenuated WSSV vaccine produced by Gamma irradiation

In this research, White spot syndrome virus (WSSV) with 105.4LD50.mL-1 inactivated with gamma irradiation at a dose rate of 14-15 kGy.sec-1 was used as a vaccine. Three hundred and sixty shrimp of Litopenaeus vannamei, medium body weight (MBW) 1.0±0.17g), were prepared and experimentally exposed. They were distributed among four groups, inclusing vaccinated-virus exposed (T1), vaccinated-nonvirus exposed (T2), virus exposed (Positive control as T3) and non-vaccinated-non-virus exposed (Negative control as T4). The mortality percent of T1 started from day 5 and reached the highest (50%) on day 11 and remained constant until end of the experiment. In T2, no mortality was observed until the 3rd day and the maximum mortality (20%) was observed on day 9. On the other hand, no remarkable mortality was recorded for T4 unlike T3 in which the mortality started on day 2 and stopped on day 7. The minimum density of hyalinocyte was calculated in T4 but the maximum one was found in T3 (17.77±0.33) with no significant differences (p < /em>