Figure 4. Viral spread of wt VACV in infected animals.

Groups of 3 C57BL/6 mice were infected intranasally with 10⁶ pfu of wt VACV. Animals remained untreated (A) or were treated one day post-infection with 10⁷ pfu of v50ΔB13RMγ (B). Replication of v50ΔB13RMγ in the tissues from the treated group was examined by X-gal staining (C). Error bars indicate the standard error of the mean. Data represent a pool of two independent experiments using 3 mice per group.