vIL10 does not affect the quantity of reactivating virus. Spleen cells were plated atop MEF cells in dilutions across 96-well plates as indicated on the x-axes with 16 duplicate wells per dilution. Wells were scored for CPE on days 10, 14 and 21. Curve-fit lines represent results of nonlinear regression analysis. Data points represent the mean of two independent experiments with spleens pooled from five mice per experiment. Results indicate no difference between MHV-76 and recombinants with or without vIL10.