Fig. 3From: Immunogenicity and protective efficacy of Salmonella enterica serovar Pullorum pathogenicity island 2 mutant as a live attenuated vaccine candidateStimulation index (SI) of chicken lymphocyte samples determined by peripheral lymphocyte proliferation assay using soluble antigen. Vaccinated group and control group refer to Fig. 1. Values represent the mean ± SEM. *Significant difference compared to the control group, P < 0.05Back to article page