Inclusion Criteria

Subjects must have:

• Normal history and physical exam.
• HIV negativity by ELISA.
• CD4 count >= 400 cells/mm3.
• No clinically significant medical disease.
• No history of immunodeficiency, autoimmune disease, or use of immunosuppressive medication.
• No prior HIV vaccines.
• Classification in one of the eligible risk groups defined in the Disease Status field.

Eligible higher risk groups:

• Heterosexual teenagers and young adults (ages 16-28 permitted) who have attended a clinic for sexually transmitted diseases in the last 3 months or have higher risk sexual behavior.
• Homosexually active males who are practicing higher risk behavior (ages 18-60).
• Injection drug users active within the past 3 years (ages 18-60).
• Heterosexual partners of HIV seropositive individuals (ages 18-60).

Eligible lower risk groups:

• Homosexually active males who are practicing lower risk behavior (ages 18-60).
• Adult women and heterosexual adult men practicing lower risk sexual behavior (ages 18-60).

Exclusion Criteria

Prior Medication:

Excluded:

• Prior HIV vaccines.
• Prior immunosuppressive medications.
• Experimental agents within the past 30 days.
• AS PER AMENDMENT 07/02/97: Use of systemic steroids in the past month (for volunteers undergoing DTH testing).

AS PER AMENDMENT 07/02/97:

• History of eczema or allergic-type reactions to vaccines used in protocol 201 (for volunteers undergoing DTH testing).