Fig. 1.

Kinetics of IFN-γ responses in infected goats. The release of IFN-γ was measured by ELISA after in vitro stimulation of whole blood with different antigens. The results are expressed as mean ΔOD₄₅₀ responses with 95% CI. The dashed horizontal line is the cutoff point for positivity. (A) PPD-B and PPD-A. **, P < 0.005; significant differences were determined by a nonparametric Mann-Witney-Wilcoxon test. (B) PPD-B, ESAT-6/CFP-10, and Rv3615c. *, P < 0.05; significant differences were determined by a nonparametric Friedman test with a post hoc Mann-Whitney-Wilcoxon test.