FIG 3.

Correlation of the MPB83/MPB70-specific IgG/IgM ratio after the initial skin test (CFT) with subsequent delayed-type hypersensitivity responses (i.e., CCT results) ∼3 months later. Antibody responses to MPB83 and MPB70 were measured by a DPP reader in relative light units (RLU) and are presented as IgG/IgM ratios. Values represent the peak antibody responses for individual animals (n = 8) after injection of M. bovis PPD for the initial skin test (i.e., CFT). Skin test responses for the CCT are presented as the change in skin thickness in response to M. bovis PPD minus the change in skin thickness in response to M. avium PPD (in millimeters). Responses were correlated (Pearson's r = −0.81).