Clinical and Molecular Observations.

Two animal challenge studies utilized 6×103 pfu; for West African MPXV this is 0.05×LD50 (A) and for Congo Basin MPXV 1×LD50 (B). Additionally a low-dose Congo Basin MPXV challenge (0.1×LD50) (C) was done. For each study, eight cages with holes on one side were utilized to individually cross-house eight animals. One challenged animal was cross-housed from an uninfected animal from the time of exposure of the challenged animal. Observations of disease and molecular findings are shown for primary MPXV challenged prairie dogs (bold-print) and naive prairie dogs; animals in the table are paired in the same primary challenged/naive pairs as was utilized during the study (i.e. PD8141 was housed across from PD8145). The days the sample tested positive are shown for viral DNA in blood, viral DNA in oral secretions and virus in oral secretions.*No serum on previous two collection days;**missing sample;NT Not Tested.