Table 1.
Survival against an i.m. challenge and antibody response of guinea pigs after single injection of rPA vaccine
| PA(μg) dose | Survival percentage (alive/total) | Geometric mean ELISA titer (standard error) | Geometric mean ED50 TNA assay titer (standard error)a |
|---|---|---|---|
| 50 | 50 (3/6) | 634.96 (1.89) | 59.01 (1.27) |
| 25 | 16.7 (1/6) | 400.00 (1.55) | 27.41 (1.31) |
| 12.5 | 0 (0/6) | 224.49 (1.45) | 18.66 (1.82) |
| 6.3 | 0 (0/6) | 1.0 (1.00) | 1.0 (1.00) |
| 3.1 | 0 (0/6) | 1.0 (1.00) | 1.0 (1.00) |
| 1.6 | 0 (0/6) | 1.0 (1.00) | 1.0 (1.00) |
| 0 (control) | 0 (0/6) | 1.0 (1.00) | 1.0 (1.00) |
aED50, reciprocal of the dilution that neutralized 50% of in vitro LeTx cytotoxicity.
Guinea pigs received single i.m. injections (0.5 ml) of rPA vaccine containing various concentrations of rPA. Four weeks later, guinea pigs were challenged by the i.m. route with a targeted dose of 30LD50 spores of the B anthracis H9401 strain. Sera were tested in a anti-PA IgG Titer and TNA assay.