TABLE 4.
Immunogenicity and protective efficacy of the III-α2r conjugate vaccine in micea
| Immunizing antigen | Dose of immunization (μg/mouse)b | No. of pups alive/total no. of pups (% survival)c | Geometric mean titer of type III CPS-specific IgGd |
|---|---|---|---|
| III-α2r | 0.5 | 12/36 (33)* | 1,131 |
| III-α2r | 5 | 32/41 (78)** | 9,051 |
| III-α2r | 20 | 36/38 (95)*** | 20,278 |
| III-TT (positive control) | 2 | 45/46 (98) | 76,472 |
| Saline (negative control) | 0 | 8/45 (18) | 109 |
a
Protection of neonatal mice against type III GBS challenge was tested.
b
Mice were immunized at days 0, 21, and 42.
c
Pups were challenged with GBS strain M781. Compared to saline, P values were as follows: *, 0.1258; ** and ***, <0.0001. Compared to III-TT, P values were as follows: *, <0.0001; **, 0.053; and ***, 0.5872.
d
Blood was drawn at day 60; values are geometric means for four sera.