Survival in juvenile shrimps (Penaeus vannamei) exposed to inactive against active white spot virus: a challenge bioassay perspective

White spot syndrome virus (WSSV) has damaged the Ecuadorian shrimp culture industry severely. The shrimp industry is highly important as it has generated high revenues over the past few years in Ecuador. Therefore, research on preventing devastating viral infections such as WSSV, is of major relevance. This study aimed to evaluate a potential adaptive immune response system in white shrimps ( Penaeus vannamei ) by using a vaccination method of inactive white spot virus (WSV) against an active WSV. A bioassay using 120 shrimps, 60 injected with inactive WSV and 60 injected with shrimp tissue without WSV infection, was conducted. Firstly, 30 specimens injected with inactive WSV were challenged against active WSV after 48 hours. The remaining 30 specimens were challenged against shrimp tissue without WSV infection, as a negative control. Secondly, 60 specimens injected with tissue without WSV infection were challenged as follows: 30 against active WSV and 30 against shrimp tissue without WSV infection. Kaplan-Meier analysis ( P £ 0.961) of the results showed no significantly differences between the groups. Thus, these results showed a non-prevention immune response effect in juvenile shrimps ( P. vannamei ) via injection.