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.