Table 1.
Rats Develop Neutralizing Antibody Titers and Are Protected from Pneumonic Plague by Vaccination with LcrV or V10
| Antigen | Survival* | IgG1† | IgG2a† | 400 μg IgG‡
|
200 μg IgG‡
|
100 μg IgG‡
|
||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Survival | MTTD§ | MPI¶ | Survival | MTTD§ | MPI¶ | Survival | MTTD§ | MPI¶ | ||||
| Alhydrogel | 0/10 | NT | NT | 0/10 | 5.1 ± 0.5 | NT | 0/10 | 5.1 ± 0.5 | NT | 0/10 | 5.1 ± 0.5 | NT |
| LcrV | 10/10 | 37,500 | 37,500 | 2/10 | 11.1 ± 3.2 | 0.4 | 1/10 | 8 ± 1.9 | 0.7 | 0/10 | 6.2 ± 1.2 | 0.9 |
| V10 | 10/10 | 37,500 | 7500 | 7/10 | 11.7 ± 1.0 | 0.1 | 0/10 | 9 ± 2.3 | 0.6 | 0/10 | 6.7 ± 1.2 | 0.8 |
*
Survival against intranasal challenge with 7500 MLD Yersinia pestis CO92 (1 × 107 cfu). Two independent vaccination and challenge experiments were performed. Results shown are from a representative experiment.
†
Antibody titer to LcrV as determined by ELISA.
‡
Rat LcrV or V10 antibody dose delivered for passive transfer of immunity to bubonic plague in BALB/c mouse model.
§
MTTD: Mean time to death; unpaired Student’s t-test gave P < 0.04 for the 400-μg dose, P < 0.05 for the 200-μg dose, and P = 0.2 for the 100-μg dose.
¶
MPI: Mouse protection index.