TABLE 4.
Mouse protection against virulent S. sonnei challenge
| Vaccine (plasmid) or controla | Survivors/totalb |
|---|---|
| S. enterica serovar Typhi Ty21a (pXK45) | 8/8 |
| S. enterica serovar Typhi Ty21a (pXK65) | 8/8 |
| S. enterica serovar Typhi Ty21a | 0/8 |
| Saline | 0/8 |
a
Vaccine strains containing plasmids or control Ty21a alone were suspended in saline to a concentration of 2.5 × 107 cells per 0.5-ml dose for intraperitoneal immunization. Saline (0.5 ml) served as a control.
b
Each mouse was challenged intraperitoneally with 5 × 105 CFU of S. sonnei 53GI (i.e., 100 × LD50) in 0.5 ml of saline containing 5% hog gastric mucin and was monitored for 4 days.