Lethal CCHFV infection in mice treated with 5A3. (A) BL6 mice (n = 8/group) were infected and at 24 h postinfection were treated with 5A3. Survival and group weights were monitored for 15 days and plotted using Prism software. (B) Mice were infected with CCHFV in the presence or absence of 5A3, and the viral RNA titers in serum, liver, and spleen were examined on days 2 and 4 by qRT-PCR (n = 3/group). Mean titers ± SD for the PFU equivalents (PFUe) were graphed. Statistical significance was determined by two-way ANOVA. *, P < 0.05; ***, P < 0.005. (C) The numbers of PFU of virus were determined in the liver and spleen on days 2 and 4 by plaque assay. Mean titers as the number of PFU per gram of tissue ± SD (n = 3/group) were graphed. The black dashed lines mark the limit of assay detection. (D) Inflammatory cytokines and chemoattractants were measured from serum (n = 3/group) on days 2, 3, and 4. Statistical significance was determined by two-way ANOVA. *, P < 0.01; **, P < 0.005; ***, P < 0.001.