TABLE 3.
Protection of mice immunized with recombinant Pht proteins from heterologous S. pneumoniae challenge
| Immunogen (Pht protein) | No. of mice alive/total no. of mice challenged with:a
|
||||
|---|---|---|---|---|---|
| SJ2 (type 6B) | EF6796 (type 6A) | EF5668 (type 4) | WU2 (type 3) | N4 (type 4) | |
| PhtA | 10/10∗ | 7/10∗ | 0/10 | 1/10 | 1/10 |
| PhtB | 8/10∗ | ND | ND | ND | ND |
| PhtD | 8/10∗ | 9/10∗ | 9/10∗ | 6/10∗ | 0/10 |
| PhtE (N-terminal) | 0/10 | 0/10 | ND | 1/10 | 0/10 |
| PhtA (N-terminal) | 9/10∗ | 5/10∗ | ND | ND | ND |
| PhtA (C-terminal) | 9/10∗ | 2/10 | ND | ND | ND |
| Sham | 0/10 | 1/10 | 0/10 | 1/10 | 0/10 |
a
Mice were challenged with either strain SJ2 (∼550 CFU; 55 × LD50), EF6796 (∼1,000 CFU; 100 × LD50), EF5668 (∼450 CFU; 90 × LD50), WU2 (∼1,500 CFU; 15 × LD50), or N4 (∼100 CFU; 20 × LD50), and deaths were recorded for up to 15 days. ∗, significantly different (P < 0.05) from sham control group as calculated by the two-sample log-rank test.
b
ND, not determined.