To the Editor: A recent article (Oct. 20 and 27 issues) describes various therapies for managing several herpesvirus infections.* In the discussion of vidarabine, the article states that the use of a more soluble analogue, vidarabine monophosphate, in herpes simplex encephalitis was curtailed because of an apparent lack of efficacy or because of increased toxicity in collaborative trials. In the final analysis of the vidarabine monophosphate limb of the multicenter clinical study sponsored by the National Institute of Allergy and Infectious Diseases, the following conclusions were reached by the Collaborative Antiviral Study Group and the manufacturer, Warner–Lambert: Patients with herpes. © 1984, Massachusetts Medical Society. All rights reserved.