TABLE 2.
Protection of rats by intranasal immunization with killed Rx1AL− cells plus CT against intrathoracic infection with serotype 3 pneumococci
| Expt | Immunogen | No. of doses | Morbidity
|
Mortality
|
||
|---|---|---|---|---|---|---|
| No. ill/ total no. (% ill) | P vs no Rx1AL−a | No. dead/ total no. (% dead) | P vs no Rx1AL−a | |||
| 1 | CT | 2 | 42/42 (100) | 29/42 (69) | ||
| CT + Rx1AL− | 2 | 18/40 (45) | <0.0001 | 18/40 (45) | 0.043 | |
| 2 | CT | 3 | 21/24 (87) | 20/24 (83) | ||
| CT + Rx1AL− | 3 | 8/25 (32) | 0.0001 | 7/25 (28) | 0.0001 | |
a
P values were calculated by the Fisher exact test between groups immunized with Rx1AL− plus CT and those immunized with CT alone.