Viremia (qPCR of viral DNA in blood) following VARV challenge by treatment group. Cynomolgus macaques were challenged with 1 × 108 PFU VARV by the intravenous route on day 0. Every third day (and at unscheduled moribund euthanasia; see data point at day 14), DNA from blood samples was evaluated by qPCR for the presence and quantitation of viral genomes. Treatment group averages are shown. Error bars indicate standard deviations. In some instances, negative error is not displayed when the error extends to negative values (less than 0), due to plotting y axis data on a logarithmic scale. Unscheduled deaths (euthanasia due to moribund condition) in the placebo group are indicated by asterisks. Plotted data for the placebo group after day 14 are representative of the three surviving animals in the group. LLOQ, lower limit of quantitation (10,000 GC/ml of blood).