DEVELOPING A VACCINE FOR PREVENTION OF NERVOUS NECROSIS DISEASE IN FARMED GROUPER IN VIET NAM.

Abstract

       The article presents the results of developing a vaccine for prevention of nervous necrosis disease in farmed grouper (Epinephelus fuscoguttatus) in Viet Nam. Master seed has been selected based on the degree of inducing sustainable protection immune responses against nervous necrosis disease and the antigenic similarity from 26 NNV isolates that have been isolated from infected grouper in six provinces/cities as Quang Ninh, Hai Phong, Nam Dinh, Khanh Hoa and Binh Thuan. The vaccine has been prepared by inactivated virus due to beta-propiolactone 0,01% and aluminum hydroxide. By the immersion method, the vaccine has been safe to Epinephelus Fuscoguttatus at larvea stage to 1.5 cm in length. The relative protection rate of vaccine has reached above 75% with the challenge dose of 0,2-1x106,8 TCID50. The relative percent of survival and the growing rate in experimental models has been higher than control models about 30-34% and 17-25%.