Effect of HSV-2 Suppressive Therapy on Sexual Behavior

Inclusion Criteria: * Age 18 years or older * HSV-2 seropositive by Western blot OR documented culture positive for HSV-2 from anogenital site * 2 or more vaginal or anal sex partners in the past 12 months * Not currently in a monogamous sexual relationship of \>= 6 months duration * Willing and able to be randomized and comply with the study protocol Exclusion Criteria: * Pregnancy or intention to become pregnant within the next year * Suppressive therapy with acyclovir, valacyclovir, or famciclovir within 2 weeks of enrollment/randomization * 6 or more symptomatic herpes recurrences in the prior 12 months or in the 12 months prior to starting suppressive therapy if on suppressive therapy during the prior 12 months * HIV seropositive or known immunocompromising medical condition. HIV negative test must be performed within 60 days of Visit 1 (enrollment/randomization). For current or former participants in HIV vaccine clinical trials for whom HIV vaccine-induced seropositivity potentially leading to vaccine study unblinding may be a concern, a report from the Seattle HVTU documenting that the participant is HIV uninfected based on HIV testing done within 60 days of Visit 1 will be accepted in lieu of HIV testing done at our clinic. * Intention to move from the Seattle area within the next year * Known allergy, intolerance, or medical contraindication to acyclovir * Inability to understand, speak, and read English