Inclusion Criteria:

• Participation in A5058s and receipt of a minimum of 7 sets of injections on that study
• Continuation of the same stable antiretroviral treatment that was given in A5058s for the last 3 months prior to A5172 entry, unless the regimen was changed for toxicity in the absence of virologic failure
• No less than 6 weeks and no more than 18 weeks since the last injection on A5058s prior to A5172 entry
• CD4+ T-cell count > 300 cells/mm3 obtained within 30 days prior to study entry
• HIV-1 RNA < 500 copies/ml obtained within 30 days prior to study entry
• Agreement to use approved methods of contraception

Exclusion Criteria:

• Pregnancy or breast-feeding
• Any of the following within 30 days prior to entry: acute infection requiring antibiotics, outbreak of herpes simplex virus (HSV) or herpes zoster, other acute medical illness, or surgery
• Symptomatic chronic infections other than HIV
• Malignancy that may require systemic therapy
• History of lymph node irradiation
• Use of immunoenhancing or immunosuppressive drugs within 30 days prior to entry, or any underlying disease of sufficient severity that these excluded drugs may be prescribed
• Hydroxyurea within 30 days prior to study entry
• Use of GM-CSF, G-CSF, M-CSF, IFN, IL-2, or other cytokines within 30 days prior to study entry
• Active drug or alcohol use or dependence that would interfere with adherence to study requirements
• Serious illness requiring systemic treatment and/or hospitalization until patient either completes therapy or is clinically stable on therapy for at least 30 days prior to study entry