Frequency of positive pox-antigen immune cells in the blood.

*granulocytes and monocytes cannot be clearly distinguished by FSC/SSC gating in some samples when virus infection is severe. Thus the two populations were gated together as one population for analysis. Value is the subtraction of isotype control staining from the pox-antigen staining result. The data does not include result from survivors, which all gave a value **for the NHPs that reached moribund after day 8, day 8 analysis was included in the table. Otherwise, the data from necropsies between day 5 and day 8 was included.