| Summary |
In this project, we select the field virus with high virulence and antigenecity as the seed virus for vaccine, strain 90-grouper for iridovirus and strain 94-471 for nervous necrosis virus.
To evaluate the efficacy of vaccine, we determine the half lethal dose of suspected hosts like sea bass, grouper, crimson snapper to decide challenge dose, different combination of adjuvants and routes of administration for development an univalent or bivalent vaccine. The results shows the suspected hosts like sea bass, grouper and crimson snapper all sensitive to iridovirus, whose LD50 for sea bass, grouper and crimson snapper were to 104.5TCID50/ml, 106.5TCID50/ml and 105.9TCID50/ml respectively. In nervous necrosis virus, the suspected hosts were sea bass and grouper, whose LD50 were 104.6TCID50/ml and 106.9 TCID50 /ml respectively. We found 0.1％ formalin inactive vaccine at 4℃had 60％ protective index higher than at 37℃; the efficacy of univalent inactive iridovirus vaccine with adjuvants B is better than with adjuvants A and C. The protective indexes in vaccine mixed with adjuvants B and delivered by intraperitoneal injection is 73％; the vaccine mixed with MVP adjuvants and delivered by intramuscularly injection is 50％. The route of vaccine delivery by
intraperitoneal injection is better than intramuscularly injection. The preliminary results for the efficacy of univalent inactive nervous necrosis virus or bivalent vaccine indicated that the
inactivation of virus at 37℃was better than at 56℃and 70℃.
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