Inclusion Criteria

Volunteers must have:

• Normal history and physical exam.
• HIV negativity.
• Absolute CD4 count >= 400 cells/mm3.
• Normal urine dipstick with esterase and nitrite.
• Lower risk sexual behavior.

Exclusion Criteria

Co-existing Condition:

Subjects with the following symptoms or conditions are excluded:

• Positive hepatitis B surface antigen.
• Medical or psychiatric condition (such as recent suicidal ideation or present psychosis) that precludes compliance.
• Active syphilis. NOTE: Subjects with serology documented to be a false positive or due to a remote (> 6 months) treated infection are eligible.
• Active tuberculosis. NOTE: Subjects with a positive PPD and a normal chest x-ray showing no evidence of TB and not requiring isoniazid therapy are eligible.

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.
• History of serious allergic reaction to any substance, requiring hospitalization or emergent medical care (e.g., Stevens-Johnson syndrome, bronchospasm, or hypotension).
• Prior psychiatric condition (such as history of suicide attempts or past psychosis) that precludes compliance.
• History of cancer unless there has been surgical excision that is considered to have achieved cure.

Prior Medication:

Excluded:

• Live attenuated vaccines within 60 days prior to study entry. NOTE: Medically indicated killed or subunit vaccines (e.g., influenza, pneumococcal) do not exclude if administered at least 2 weeks from HIV immunizations.
• Experimental agents within 30 days prior to study entry.
• 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 past 12 months.
• Higher risk sexual behavior.