Inclusion Criteria:

The study will include subjects who meet all of the following criteria:

• Male or female, between 18 to 60 years of age at the time of the first vaccination
• Informed consent signed prior to all study procedures
• No evidence of acute HIV seroconversion in the 12 months prior to the initiation of antiretroviral therapy
• Receiving a potent antiretroviral drug regimen for a minimum of 12 consecutive months prior to screening with no interruption of therapy for > 2 weeks.

A potent antiretroviral drug regimen is defined as any of the following: *two nucleoside reverse transcriptase inhibitors with either a protease inhibitor or a non-nucleoside reverse transcriptase inhibitor; *a boosted protease inhibitor with either one or two nucleoside reverse transcriptase inhibitors or a non-nucleoside reverse transcriptase inhibitor.

• Documented suppressed HIV-1 RNA. Subjects must have plasma HIV-1 RNA values <50 copies/ml on at least two measurements during the 6 months prior to the study entry.
• CD4+ T cell count >400 cells/mm3 within 45 days of the first vaccination
• CD4 count >200 cells/mm3 at all times

• Laboratory values within 45 days prior to the first vaccination that meet the following criteria:

  • Hemoglobin >9.0 g/dL;
  • Absolute neutrophil count ≥ 1000/mm3;
  • Platelet count ≥ 75,000/mm3;
  • Prothrombin time (PT) < 1.2 x upper limit of normal (ULN) and partial thromboplastin time (PTT) < 1.5 x ULN;
  • Total serum creatinine < 1.3 x ULN;
  • Total serum bilirubin < 2.0 x ULN;
  • Alkaline phosphatase, AST (SGOT) and ALT (SGPT) < 1.5 x ULN.
• Negative serologic test for HBsAg
• Negative serologic test for antibodies to HCV or negative HCV PCR if anti-HCV antibodies are positive.

• Female patient of childbearing potential must:

  • Have a negative urine pregnancy test (sensitive to 25 IU HCG) immediately prior to vaccination;
  • Have no intention of conceiving during the entire study period;

  • Agree to use an effective method of birth control during the entire study period. Effective methods of birth control include:

    1. Condoms (male or female) with or without spermicidal agent. Condoms are recommended because their appropriate use is the only contraception method effective for preventing HIV transmission;
    2. Diaphragm or cervical cap with spermicide;
    3. Intrauterine device (IUD). An IUD is an adequate method of birth control, but increases the risk of pelvic inflammatory disease;
    4. An FDA-approved oral contraceptive, provided there is no interaction with the woman’s current antiretroviral therapy or other medications;
  • If participating in sexual activity that could lead to pregnancy, the male subject or his partner must also use contraception.

Exclusion Criteria:

• HIV-1 RNA > 50 copies/mL within 6 months of screening.
• Received antiretroviral therapy within 12 months of known HIV-1 seroconversion.
• History of clinically significant cardiac, pulmonary, gastrointestinal, hepatic, renal, pancreatic, or neurological disease
• Recent (<24 hours) febrile illness on the day of vaccination (temperature >101 degrees F, oral)
• History of CD4 count <200 cells/mm3.
• Female subject who is pregnant or nursing a child
• Received any immune globulin or blood products within 3 months prior to vaccination or plans to receive such products during the study
• Received any live vaccine within 30 days prior to study vaccination or any inactivated vaccine within 14 days prior to study vaccination
• Previously participated in any HIV vaccine clinical trial (unless it is documented that the subject received only placebo)
• History of any AIDS defining illness
• Any change in antiretroviral drug regimen within 12 weeks prior to screening
• Use of any immunomodulatory agents within 30 days prior to study enrollment or planned use during the trial
• Active drug or alcohol use or dependence that, in the opinion of the sponsor, would interfere with adherence to study requirements.
• Any condition or history of illness which, in the opinion of the investigator, might interfere with the evaluation of the study objectives
• Subject has a history of anaphylaxis to any vaccine
• Subject has a history of allergy to any adjuvant component
• Subject is taking any of the following medications: systemic steroids (inhaled or nasal steroid therapy is permitted), interleukins, systemic interferons (e.g. local injection of interferon alpha for treatment of HPV is permitted) or systemic chemotherapy