WT C57BL/6 mice were inoculated in the left rear footpad with 1,000 PFU of AF15561 or 181/25 (n = 5–8 mice per group). At the time points shown, a virion-based ELISA was used to quantify the serum endpoint titers of CHIKV-specific (A) IgM or (B) IgG.
(C) IgG subtype-specific detection antibodies were used to quantify IgG subtypes present in serum at 28 dpi (n = 5–6 mice per group). Data are from two or more independent experiments. P values were determined by two-way ANOVA with a Bonferroni’s multiple comparison test (A, B) and Student’s t-test (C). *, P <0.05, **, P < 0.01; ***, P < 0.001, ****, P < 0.0001.