Inclusion Criteria

Subjects must have:

• Normal history and physical exam.
• Negative test for HIV by ELISA within 6 weeks prior to immunization.
• Negative test for HIV by Western blot.
• CD4 count >= 400 cells/mm3.
• No history of smallpox vaccination.
• Normal urine dipstick with esterase and nitrate.
• No history of immunodeficiency, chronic illness, autoimmune disease, or use of immunosuppresssive medications.

Exclusion Criteria

Co-existing Condition:

Subjects with the following conditions are excluded:

• Positive for hepatitis B surface antigen.
• Medical or psychiatric condition or occupational responsibilities that preclude compliance.
• Active syphilis (NOTE: If serology is documented to be a false positive or due to a remote (> 6 months) infection, subject is eligible).
• Active tuberculosis (NOTE: Subjects with a positive PPD and normal x-ray showing no evidence of TB and who do not require INH therapy are eligible).
• Eczema.

Household contact with persons meeting any of the following criteria:

• pregnancy, < 12 months of age, eczema, or immunodeficiency disease or use of immunosuppressive medications.

Subjects with the following prior conditions are excluded:

• History of anaphylaxis or other serious adverse reactions to vaccines.
• Eczema within the past year.
• PER 8/94 AMENDMENT: History of cancer unless surgically excised with reasonable assurance of cure.
• PER 8/94 AMENDMENT: History of serious allergic reaction requiring hospitalization or emergent medical care.

Prior Medication:

Excluded:

• Prior HIV vaccines.
• Live attenuated vaccines within the past 60 days. NOTE: Medically indicated subunit or killed vaccines (e.g., influenza, pneumococcal) do not exclude but should be administered at least 2 weeks prior to HIV immunizations.
• Experimental agents within the past 30 days.

Prior Treatment:

Excluded:

• Blood products or immunoglobulin within the past 6 months.

Higher risk behavior for HIV infection as determined by screening questionnaire, including:

• History of injection drug use within 12 months prior to study entry.
• Higher or intermediate risk sexual behavior.