FIG. 3.

Efficacy of MPL and TDB as immunomodulators in an ESAT-6 subunit vaccine. Testing of MPL and TDB in combination revealed a strong additive potential as assessed by IFN-γ production, but this was not reflected in a correspondingly high level of protection. (A) Systemic immune responses determined by IFN-γ production after in vitro restimulation with ESAT-6 of PBMCs harvested from mice (four per group) 1 week after the final immunization (blood was pooled within groups). Results are presented as means of triplicate wells ± standard deviations. (B) Protective efficacy of the vaccines, expressed as the log₁₀ reduction in bacterial load in the lung, compared to the unimmunized group (naïve). Results are from four mice per group, assayed individually. N.A., not applicable. * and **, values significantly different from the naïve control (P < 0.05 and P < 0.01, respectively).