Figure 2.

Proportion of animals surviving over time after a 24-h lethal toxin challenge (shaded area) and treated with conventional hemodynamic support alone (Hemo) or protective antigen–directed monoclonal antibody (PA-mAb) alone (mAb), or both (Hemo + mAb) or neither (placebo alone, control). The 3 panels in Figure 2A show experiments in which PA-mAb or placebo was administered at 0, 9, or 12 h, respectively. The efficacy of PA-mAb alone decreased significantly with delay in administration (P = .004 for the trend test) but not when it was combined with hemodynamic support (P = .95, trend test). Figure 2B displays proportional survival in animals in the 3 groups shown combined over all 10 experiments, irrespective of timing of PA-mAb. Because the effects of PA-mAb alone differed significantly with time of administration, survival data from this group could not be combined over experiments and are not presented in panel B. Two-group comparison P values labeled in Figure 2B were based on exact log-rank tests.