Piscirickettsiosis, or salmonid rickettsial septicemia (SRS), caused by Piscirickettsia salmonis, has severely challenged the sustainability of the Chilean salmon industry since its appearance in 1989. P. salmonis has become a serious problem in confined salmon-rearing in Chile, and a number of vaccines have been designed and commercialized, so far with moderate effect. This chapter discusses the occurrence, significance, etiology, and pathogenesis of piscirickettsiosis. It then describes the different vaccination procedures and the effects and side-effects of vaccination. The first P. salmonis vaccines were formulated as formalin-inactivated bacterins, using cell-culture derived organisms grown in CHSE-214 cells, derived from Chinook salmon embryonic cell culture. The first bacterin-vaccination studies showed the potential of formalin-inactivated P. salmonis bacterins as immunogenic agents against SRS. Bacterial challenge in vaccine/control trials is complex, with different outcomes depending upon strain type, dose and route of administration.
- Fish vaccination
- P. salmonis