Part A: 60 approved HIV infected patients will be randomized to either suppressive ACV therapy or matching placebo for 12 weeks. Serology for HSV serum antibodies will be obtained at screening and a full history and physical exam will be performed on Day 1 and interval examinations at Weeks 2, 4, 8 and 12. Extensive clinical exams will be conducted on a regular schedule throughout the 12 weeks.