ABSTRACT
Objective:Selected virulence factors more than and high virulent Aeromonas hydrophia strain made into inactivated vaccine,to study the immunization effect of inactivated vaccine.Methods:Crucian were vaccinated with formalin-killed vaccine via in-traperitoneal injection.Controls were injected with the same volumes of saline.Then the antibody titres, histopathology and relative percent survival were analyzed from samples of both groups.Results: The antibody in the indirect agglutination reaction could be detected in vaccinated fish once a weeks after immunization and reached highest level 6 weeks after immunization.The histopathology analysis indicated that the vaccine had a good protective effect on crucian target organs.Vaccinated fish showed 100%relative percent survival and the immune period would be 6 month.Conclusion:The vaccine in this study has a significant protective effect on crucian and may be used as effective fish vaccines against bacterial septicemia.