Figure 8. Protection of hSCARB2-Tg mice from 5746 challenge by formalin-inactivated E59 vaccine.

Survival of hSCARB2-Tg mice intramuscularly pre-immunized twice with (Δ) or without (▴) 1 µg of FI-E59 on Day 1 and Day 8 of birth prior to being challenged with 3×10⁶ pfu of 5746 s.c. Twelve mice in the FI-E59 vaccine-treated group and 13 mice in the untreated group were examined. Logrank test was used for statistical analysis. (B) After the immunization of 1 µg of FI-E59 on Day 1 and Day 8 of birth, mice were sacrificed on Day 14 of birth and the spleens were pooled from 3 individual mice and the isolated 5×10⁵ splenocytes per well were subjected to the IFN-γ and IL-4 ELISPOT assays. Data are representative of the results derived from 2 independent experiments, each with 4 mice per group. (C) Serum samples collected from individual mice on Day 14 of birth prior to being challenged with 3×10⁵ pfu of 5746 s.c. were assayed for the titer of anti-E59 and anti-5746 neutralizing antibodies described in the Materials and Methods section. The results were expressed as titers for each test sample. Bars correspond to the mean titers for each experimental group. Unpaired student t test with Welch’s correction was used for statistical analysis of (B) and (C).