TABLE 4.
Vaccine efficacies of live attenuated S. Typhimurium CVD 1931 (S. Typhimurium D65 ΔguaBA ΔclpX) and CVD 1944 (S. Enteritidis R11 ΔguaBA ΔclpX) against heterologous serogroupsa
| Immunization | Challenge | Challenge dose (LD50) | Mortality rate | Vaccine efficacy (%) | P valueb |
|---|---|---|---|---|---|
| PBS | S. Enteritidis R11 | ∼50 | 11/15 | ||
| CVD 1931 | 5/14 | 51 | 0.07 | ||
| PBS | S. Typhimurium D65 | ∼200 | 12/15 | ||
| CVD 1944 | 2/13 | 81 | <0.001 |
a
Mice were immunized orally with 109 CFU three times, with 1 month between immunizations, and orally challenged 1 month later with 1.2 × 106 CFU of S. Enteritidis R11 or 3.9 × 106 CFU of S. Typhimurium D65. The mice were monitored daily for 28 days.
b
Fisher's exact test (two tailed).