Virus titers of V3000 and V3043 in IFN-α/βR−/− mouse tissues. Six- to 8-week-old IFN-α/βR−/− mice were inoculated s.c. in the LRFP with 103 PFU of V3000 (solid bars) or V3043 (hatched bars). At the indicated times p.i., three mice per group were sacrificed, tissues were harvested, and virus titers were determined as indicated in Fig. 1. The following tissues were harvested: DLN (A), spleen (B), serum (C), and brain (D). The values are the geometric mean titers (log10 PFU/milliliter or gram) of three mice. Error bars represent the standard deviations. The lower limit of detection is indicated as a broken line. ∗, samples with virus titers below the limit of detection.