Potentiality of a live vaccine with nervous necrosis virus (NNV) for sevenband grouper Epinephelus septemfasciatus at a low rearing temperature

► Mortality of fish due to NNV were reduced by decreasing fish rearing temperature. ► No mortality was observed in the fish reared at 17 °C. ► The survivors mounted a specific protective immune response against NNV. ► NNV titer was far below the NNV critical level but above the threshold level. ► Suggesting the potentiality of a live NNV vaccine by rearing fish at 17 °C.