Evaluation of vaccines against P. salmonis: analysis of acquired versus innate immune response (P4055)

Abstract

Abstract The Salmonid Rickettsial Septicaemia (SRS) is one of the most damaging syndrome that affects salmon farming in Chile. The causal agent of this pathology is the bacterium called, Piscirickettsia salmonis and vaccination remains the best way to reduce the economic impact caused by this disease. Several vaccines are used based in bacterins and recombinant proteins. However, the modulation of the innate and humoral immune response has not been determined. Thus 3 prototypes vaccines were used to evaluate the functionality of cellular components of P. salmonis in the modulation of immune response. In order to evaluate the immunogenicity produced by the prototype AUSTTRAL-SRS vaccine in Atlantic salmon. We designed a trial where we injected three groups of fish with three different formulations in two doses. After three weeks, the fish of each group were challenged with a lethal dose (LD70) of P. salmonis. The result obtained by studying the interleukin gene expression, ROS and lisosyme analysis let us to conclude that the three prototype vaccines were able to largely stimulate the innate immune response. However, only one prototype was efficient to stimulate the specific acquire immune systems in fish and also was highly efficient to protect the vaccinated salmon against SRS. These results indicate that the used marker of the innate immune system were not a good vaccine markers compared with acquire immune response. INNOVA 11IDL2-10523