Fig. 5.

Co-administration of BCV and ACAM2000 protects C57BL/6 mice from a lethal ectromelia virus challenge when given up to 1 day post-challenge but does not protect against weight-loss. C57BL/6 mice were vaccinated with ACAM2000 (2x10⁵ PFU) or vehicle and treated with BCV or Anti-Veh at Day -1, 0 or 1 relative to vaccination. The BCV dosing regimen consisted of a 20 mg/kg oral gavage treatments followed by an additional 4 treatments of 20 mg/kg administered every 3 days for a total of 5 doses. The same regimen was used for vehicle treated animals. Blood was obtained at 21 and 50 days post-vaccination for measurement of antibody (ELISA) and CD8⁺ T cell responses. Mice were challenged at Day 52 (Day 0 relative to challenge) by the intranasal route with 4000 PFU (40× LD₅₀) of ECTV and weight changes are shown. Representative experiment of N = 2 with 18–20 mice/group. Error bars indicate SEM.