PTPRC and viral infectious disease: Viral load (VL, copies/ml blood) peaked at eight weeks after viral infection and all infected animals had sustained VL (7.05 × 105 to 1.5 × 107) until 16 weeks where reductions in total human cells (as measured by CD45) mirrored decreases in VL (4.77 × 103 to 5.1 × 106).