A Randomized Trial to Evaluated the Suppressive Effect of Acyclovir on Rapidly Cleared HSV-2 Reactivation

Inclusion Criteria: COHORT 1: HIV seronegative 1. Older than 18 years; 2. HSV-2 seropositive by Western Blot; 3. not receiving any drugs with known anti-HSV-2 activity for study duration; 4. women of child bearing potential who are sexually active with men must be using a medically accepted method of contraception as judged by the investigator; 5. women of child-bearing potential must have a negative pregnancy test (urine) at screening visit; 6. in general good health, without other serious medical conditions and specifically with normal renal and hepatic function, as determined by the patient's medical history; 7. planning to remain resident in the area of the study center for the duration of the study participation; 8. HIV seronegative COHORT 2: HIV seropositive 1. Older than18 years; 2. HSV-2 seropositive by Western Blot; 3. not receiving any drugs with known anti-HSV-2 activity for study duration; 4. women of child bearing potential who are sexually active with men must be using a medically accepted method of contraception as judged by the investigator; 5. women of child-bearing potential must have a negative pregnancy test (urine) at screening visit; 6. in general good health, without other serious medical conditions and specifically with normal renal and hepatic function, as determined by the patient's medical history; 7. planning to remain resident in the area of the study center for the duration of the study participation; 8. HIV seropositive 9. CD4 count over 250 cell/mm3 10. Not taking antiretroviral therapy Exclusion Criteria: For both cohorts: 1. hypersensitivity to acyclovir or valacyclovir; 2. pregnant women; 3. Taking immunosuppressive therapies, such as chronic oral steroids or immune modulatory drugs. For cohort 2: 1. CD4 count\<250 cell/mm3 2. Taking antiretroviral therapy at the time of study entry