DAO 36:73-75 (1999)  -  doi:10.3354/dao036073

Effectiveness of a vaccine against red sea bream iridoviral disease in a field trial test

Kazuhiro Nakajima1,*, Yukio Maeno1, Atsushi Honda2, Kenichi Yokoyama3, Tetsurou Tooriyama3,Sadao Manabe3

1National Research Institute of Aquaculture, Fisheries Agency, Nansei, Mie 516-0193, Japan
2Nagasaki Prefectural Institute of Fisheries, Taira, Nagasaki 851-2213, Japan
3Research Foundation for Microbial Diseases of Osaka University, Yahata, Kanonji, Kagawa 768-0061, Japan

ABSTRACT: Since 1990, red sea bream iridovirus (RSIV) has caused high mortalities in the summertime in cultured red sea bream Pagrus major in southwest Japan. To establish control measures for red sea bream iridoviral disease (RSIVD), the effectiveness of a formalin-killed viral vaccine was evaluated in a field trial. Two groups each consisting of 1000 juvenile red sea bream were either intraperitoneally inoculated with vaccine (vaccinated group) or were not vaccinated (non-vaccinated group). After vaccination, the fish were held for 1 wk, then transferred to a marine net pen and observed for 12 wk. The cumulative mortalities caused by RSIVD in the vaccinated group or control group were 19.2 and 68.5%, respectively. Additionally, the presence of virus antigen in the spleen was investigated and body weight was measured 6 and 12 wk post vaccination. In the vaccinated group, viral antigen was not detected. The increase in body weight of vaccinated fish was significantly (p < 0.05) greater than that of control fish. These results suggest that the vaccine against RSIVD was effective in 1 field trial.


KEY WORDS: Red sea bream iridoviral disease · Iridovirus · Viral disease · Marine fish · Natural infection · Vaccination


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