A Multicenter, Randomized, Placebo-Controlled, Double-Blind Trial to Evaluate the Safety and Immunogenicity of the Therion Recombinant Vaccinia-HIV-1 IIIB ENV/GAG/POL Vaccine (TCB-3B) and MN RGP 120/HIV-1 In Alum.

Inclusion Criteria Patients must have: Negative FDA-approved ELISA for HIV within 8 weeks of immunization. Normal history and physical examination. Negativity for Hepatitis B surface antigen. Availability for follow-up for planned duration of the study (18 months). Exclusion Criteria Co-existing Condition: Patients with the following symptoms or conditions are excluded: Medical or psychiatric condition or occupational responsibilities that preclude subject compliance with the protocol. Specifically excluded are people with a history of suicide attempts, recent suicidal ideation or who have past or present psychosis. Active syphilis. NOTE: If the serology is documented to be a false positive or due to a remote (> 6 months) treated infection, the volunteer is eligible. Active tuberculosis. NOTE: Patients with a positive PPD and a normal chest X-ray showing no evidence of TB and not requiring INH therapy are eligible. Household contacts with, or occupational exposure to, people with any of the following: Pregnancy. <12 months of age. Eczema or Immunodeficiency disease. Use of immunosuppressive medications. Patients with the following prior conditions are excluded: History of immunodeficiency, chronic illness, malignancy or autoimmune disease. History of cancer, unless there has been surgical excision followed by a sufficient observation period to give a reasonable assurance of cure. Any history of anaphylaxis or history of other serious adverse reactions to vaccines. History of serious allergic reaction to any substance, requiring hospitalization or emergent medical care (e.g., Stevens-Johnson syndrome, bronchospasm, or hypotension). Eczema within the past year. History of smallpox vaccination. Envelope bands on HIV-1 Western blot within 8 weeks of immunization. Prior Medication: Excluded: Use of immunosuppressive. Live attenuated vaccines within 60 days of study. NOTE: Medically indicated subunit or killed vaccines (e.g. influenza, pneumococcal) do not exclude, but should be given at least 2 weeks prior to HIV immunizations. Experimental agents within 30 days prior to study. Prior receipt of HIV-1 vaccines or placebo recipient in a previous HIV vaccine trial. Receipt of blood products or immunoglobulin within past 6 months. Risk Behavior: Excluded: History of injection drug use within the last 12 months prior to enrollment. Higher or intermediate risk sexual behavior as defined by the AVEG. Lower risk sexual behavior as defined by AIDS Vaccine Evaluation Group (AVEG) procedures.