Inclusion Criteria

Subjects must have:

• Normal history and physical exam.
• Negative for HIV by ELISA within 6 weeks of immunization.
• CD4 count >= 400 cells/mm3.
• Normal urinalysis.

Exclusion Criteria

Co-existing Condition:

Subjects with the following conditions are excluded:

• Medical or psychiatric condition or occupational responsibilities that preclude compliance.
• Active syphilis (volunteers are eligible if serology is documented to be a false positive or due to a remote (> 6 months) treated infection).
• Active tuberculosis (volunteers with a positive PPD and normal chest x-ray showing no evidence of TB and not requiring INH therapy are eligible).
• Hepatitis B surface antigenemia.

Subjects with the following prior conditions are excluded:

• History of immunodeficiency, chronic illness, autoimmune disease, or use of immunosuppressive medications.
• History of anaphylaxis or other serious adverse reactions to vaccines.

Prior Medication:

Excluded:

• Live attenuated vaccines within the past 60 days. NOTE: Medically indicated subunit or killed vaccines (e.g., influenza, pneumococcal) are permitted if received at least 2 weeks prior to first immunization.
• Experimental agents within the past 30 days.
• Prior HIV vaccines.

Prior Treatment:

Excluded:

• Blood products or immunoglobulin within the past 6 months.

Identifiable high-risk behavior for HIV infection, including history of injection drug use within the last 12 months prior to enrollment and higher or intermediate risk sexual behavior.