Mice lacking the Stat1 interferon signaling gene were infected with herpes simplex virus type 1 (HSV-1) or an attenuated recombinant lacking virion host shutoff (Δvhs). Δvhs virus-infected Stat1−/− mice showed levels of replication equivalent to that of the wild-type virus-infected control mice but reduced relative to wild-type virus-infected Stat1−/− mice. Stat1 deficiency relieves the immunomodulatory deficiency of Δvhs virus, but not its inherent growth defect. Also Vhs is dispensable for reactivation