Inclusion Criteria

Patients must have:

Parts A and B:

• Documented HIV infection.
• Patients >= 18 years of age must be willing and able to give informed consent and patients < 18 years must have written consent from a parent or guardian.

Part A:

• CD4+ T count < 250 cells/mm3 within 1 month prior to study entry.
• Documented antibodies to HSV any time prior to study.
• History of HSV outbreak in past 2 to 12 months.
• Former Part B patients who have completed the 12 week follow up may enter Part A after at least a 4-week washout.

Part B:

• Documented CD4+ T count < 250 cells/mm3 anytime prior to study entry.
• Oral, genital or anorectal lesions with a vesiculopustular component.
• Presumptive diagnosis of HSV.
• Former part A patients may enter part B after a 4-week washout.

Exclusion Criteria

Patients with any of the following prior conditions are excluded:

• Documented or suspected HSV within 2 months prior to study entry.
• History of infection with an acyclovir resistant HSV strain.
• History of disseminated HSV.
• History of treatment for acute CMV or MAC disease.
• History of poor medication or clinic visit compliance.

Prior Medication:

Excluded:

• Use of acyclovir, famciclovir, foscarnet, ganciclovir, valacyclovir or cidofovir for any reason within one month prior to study entry. [AS PER AMENDMENT 1/21/97: Use of antiherpes agents, both FDA-approved and investigational, including bis-POM, PMEA, lobucavir, acyclovir, etc.]
• Initiation or modification of antiretroviral therapy, immunomodulators, or any kind of vaccination within 2 months prior to study entry.
• Treatment for acute medical condition within 4 weeks prior to study entry.