Mice were immunized with 1 x 103CFU of the gidA mutant vaccine strain or sterile PBS. Serum and cells were collected 42 days later and transferred to groups of five naïve mice. All recipient mice were challenge by i.p. injection with 1 x 105 CFU of WT STM 24 hours after transfer. Morbidity and mortality of these animals were monitored for 30 days after challenge. The serum passive transfer (A) was statistically significant with a P value of 0.0414 while the cell passive transfer (B) was not statistically significant. Statistical significance was calculated using the Kaplan-Meier survival analysis with the log-rank (Mantel-Cox) significance test.