Serological assessment of acyclovir treatment of herpes genitalis

Oral acyclovir was given to 60 patients with herpes genitalis--20 experiencing a first attack and 40 with recurrent attacks. All patients were followed up for 1 year. Serial serum samples from the patients as well as from 20 controls were studied to determine the effect of therapy on the immune response to herpes simplex virus (HSV). No toxicity was observed, and very few patients had rather insignificant side effects (e.g., diarrhea). The frequency of recurrence (number of recurrences per year) of genital herpes in acyclovir-treated patients was found significantly lower than in controls. More frequent recurrences were observed in those who had high antibody titer in their early convalescent phase sera than in those without or with a low titer of such antibodies. The antibody titers were reduced in those who received acyclovir as compared with controls. The mean time to seroconversion was longer in the acyclovir-treated group than in controls. Oral acyclovir is thus effective and well tolerated in patients with herpes genitalis. Treatment with acyclovir also diminishes the humoral antibody response to HSV, but it does not prevent recurrence. The effects of acyclovir on the immune response to HSV are discussed.