C57BL/6 mice were immunized with 3 ×107 CFU Lm or Lm-OVA, then 60 days later challenged with 100 CFU Yptb-OVA. Mice were sacrificed upon observation of morbidity and (A) day of death noted. Results shown are pooled from 3 separate experiments. Lm or Lm-OVA-immune mice were challenged with 150 clones of a Lm-OVA clone library, sacrificed at days 1, 7 and output bacterial burden (B, C) and clone numbers (D, E) in the spleen (B, D) and liver (D, E) determined. ND, not detected. Results shown are from two separate experiments.