A herpes simplex virus type 1 mutant containing a deletion within immediate early gene 1 is latency-competent in mice.

We have investigated the behaviour in mice of the herpes simplex virus type 1 (HSV-1) mutant dl1403, which contains a deletion within the gene encoding the immediate early polypeptide Vmw110. The deletion was responsible for a reduction in virulence assayed by both the intracranial and footpad routes of inoculation. Following injection into the footpad, dl1403 was able to reach the spinal cord and establish a latent infection in sensory ganglia from which virus spontaneously reactivated upon explanation. The Vmw110 polypeptide is therefore dispensable for the establishment and maintenance of latency and for reactivation from the latent state.