Groups of BALB/c mice (n = 8) received a 1° and 2° i.n. vaccination of 2 µg F1, 6 µg V, and 10 µg each CRX-524 and CRX-527 on day 0 and day 10. At various times after the 1° vaccine (day 21 to day 90), groups were challenged intranasally with 100LD50s Y. pestis CO92 (2.3 × 106 CFU) and survival measured at 14 days post challenge.
A: Mice received a 1° and 2° i.n. vaccine on day 0 and day 10 (■); control groups received i.n. F1 + V (), AGPs, or PBS. Only animals receiving the i.n. vaccine were significantly protected (P < 0.0001)
B: Pooled sera total IgG titers against V and F1 were measured in animals one week prior to challenge.