Immune Therapies and Anti-HIV Therapy Withdrawal in Controlling Viral Load

Step I: In addition to continuing HAART, patients are randomized into 1 of the following 4 arms: A: Immunization placebo; B: Immunization with the canarypox HIV-vaccine (vCP1452); C: Daily low-dose IL-2 + immunization placebo; or D: Daily low-dose IL-2 + canarypox HIV-vaccine (vCP1452). Patients on Arms A, B, C, and D receive vaccine (or vaccine placebo) injections at Weeks 0, 4, 8, and 12. Patients on Arms C and D receive IL-2 by self-injection. HAART is not provided as part of this study. Step II: Patients on all arms (A, B, C, and D) who meet inclusion criteria advance to Step II and interrupt HAART for a minimum of 12 weeks. The efficacy of these immunological therapies will be determined by monitoring the dynamics of viral rebound upon cessation of antiviral therapy. After 12 weeks of Step II, patients whose viral load remains below 30,000 copies/ml remain on Step II, off HAART, and continue weekly viral load monitoring. Patients will not terminate Step II or resume HAART unless and until their viral load increases to more than 30,000 copies/ml on 3 successive determinations, or their CD4 count decreases to less than 200 cells/mm3 or less than 50 percent of the baseline CD4+ T cell concentration on 2 successive occasions.