Table 2.
Antibody responses and protective efficacy of PA and LF domains. Groups of A/J mice were immunized with 10µg the different proteins on days 0, 14 and 28, as described in Section 2. Serum samples removed prior to challenge were pooled and assayed by ELISA for IgG to PA and LF. Mice were subjected to lethal i.p. challenge (~2×105 CFU) with B. anthracis STI spores on day 70.
| Antigen | Antibody Titer (EU/ml)a | Vaccine efficacy (%) survivors/total |
||
|---|---|---|---|---|
| PA | LF | |||
| PA | 1,280,000 | N.D. | 100% | (8/8) |
| PAD4 | 1,280,000 | N.D. | 87.5% | (7/8) |
| LFD1 | N.D. | 144,000 | 100% | (8/8) |
| LFD1-PAD4 | 320,000 | 52,000 | 100% | (8/8) |
| PBS | N.D. | N.D. | 0% | (0/8) |
a
Serum antibodies were measured on day 62 post immunization.