TABLE 5.
Passive protection of mice from fatal pneumococcal infection with anti-PspA serum from mice orally immunized with S. typhimurium χ4550(pYA3193)a
| Challenge dose (log10) | Challenge route | Passive serum administered | Serum dilution | Days to death | P value vs PspA immuneb |
|---|---|---|---|---|---|
| 3.7 | i.v. | Nonimmune | 1/2 | 1, 1, 1, 1, 2, 2, 2, 2, 2 | 0.007 |
| i.v. | Vector immune | 2, 2, 3, 4, 4 | 0.029 | ||
| i.v. | PspA immune | 1/2 | 1, >21, >21, >21, >21, >21, >21, >21, >21 | ||
| 3.9 | i.v. | Nonimmune | 1/10 | 1, 2, 2, 2, 2, 2 | 0.0086 |
| i.v. | PspA immune | 1/10 | 2, 3, 3, 4, >15, >15 | ||
| 3.0 | i.p. | Nonimmunec | 1/5 | 2, 2, 2, 3, 3, 3, 4 | 0.038 |
| i.p. | PspA immune | 1/5 | 2, 3, 4, 5, >15, >15, >15 |
a
i.v. challenge studies were conducted with CBA/N recipients; i.p. challenge studies were conducted with BALB/cJ recipients.
b
P values comparing the days to death were calculated by using the Wilcoxon two-sample rank test between mice given PspA-immune sera and mice receiving vector-immune or nonimmune serum. In the case of the i.p. challenge, the P value was calculated between immune and the pooled data for nonimmune serum and no serum.
c
Includes two mice which received no serum.