Prevention of herpes simplex virus infection and latency by prophylactic treatment with acyclovir in a weanling mouse model.

Abstract

Acyclovir is an antiviral agent that inhibits acute herpes simplex virus replication and decreases the frequency of reactivation, but it is not currently used to prevent primary disease or the establishment of latency. The purpose of this study was to reexamine the efficacy of acyclovir in preventing acute and latent herpes simplex virus infection. Mice were infected by footpad inoculation with 2 viral recombinants that express beta-galactosidase. Half of each group was treated prophylactically with intraperitoneal acyclovir and then given acyclovir in the drinking water. Four days after infection, the dorsal root ganglia were removed, fixed, and stained, and the number of cells expressing beta-galactosidase were counted. Compared with placebo, prophylactic acyclovir completely inhibited acute viral replication as evidenced by the absence of beta-galactosidase activity (P < .001) and significantly decreased the number of neurons harboring latent infection (P = .01). Acyclovir prophylaxis prevented acute and reduced latent ganglionic infection with herpes simplex virus in a weanling mouse model.