TABLE 6.
Survival of mice following immunization with mutant strains of SCHU S4
| Vaccine strain | Vaccine dose | Time to death (days)c | Median time to death (days) |
|---|---|---|---|
| Intradermal challengea | |||
| None | None | 4, 5, 5, 5, 5 | 5 |
| ΔFTL0439 | 10 | >28 (5) | >28 |
| ΔfupA | 103 | >28 (5) | >28 |
| ΔpdpC ΔpdpE | 107 | 5, 13, >28 (3) | >28 |
| FSC043 | 107 | 6, >28 (4) | >28 |
| ΔpdpC | 103 | 7, 9, 25, >28 (2) | 25 |
| ΔpdpC | 107 | 5, >28 (4) | >28 |
| Intranasal challengeb | |||
| None | None | 5, 6, 6, 6, 6 | 6 |
| ΔFTL0439 | 10 | >28 (5) | >28 |
| ΔfupA | 103 | 10, 11, 21, 22, >28 | 21 |
| ΔpdpC ΔpdpE | 107 | 7, 8, 8, 9, 10 | 8 |
| FSC043 | 107 | 9, 13, 13, >28 (2) | 13 |
| ΔpdpC | 103 | 7, 7, 8, 8, 8 | 8 |
| ΔpdpC | 107 | 7, 7, 7, 8, 9 | 7 |
a
Five-week-old immune mice were challenged with 2,400 CFU of strain SCHU S4. The mice were followed for 28 days after challenge.
b
Five-week-old immune mice were challenged with 25 CFU of strain SCHU S4. The mice were followed for 28 days after challenge.
c
The numbers in parentheses are the numbers of mice with the preceding time to death when more than 1.