TABLE 2.
Vaccine efficacy of live attenuated S. Typhimurium CVD 1931 (S. Typhimurium D65 ΔguaBA ΔclpX) and CVD 1944 (S. Enteritidis R11 ΔguaBA ΔclpX)a
| Immunization | Challenge | Challenge dose (LD50) | Mortality rate | Vaccine efficacy (%) | P valueb |
|---|---|---|---|---|---|
| PBS | S. Typhimurium D65 | ∼10,000 | 12/12 | ||
| CVD 1931 | 0/12 | 100 | <0.001 | ||
| PBS | S. Enteritidis R11 | ∼10,000 | 12/12 | ||
| CVD 1944 | 2/12 | 83 | <0.001 |
a
Mice were immunized orally with 109 CFU three times, with 1 month between immunizations, and orally challenged 1 month later with 2.6 × 108 CFU of S. Typhimurium D65 and 1.5 × 108 CFU of S. Enteritidis R11. The mice were monitored daily for 29 days.
b
Fisher's exact test (two tailed).