A Phase I, Multicenter, Randomized, Double-Blind, Placebo-Controlled HIV-1 Vaccine Trial to Evaluate the Safety and Immunogenicity of rgp120/HIV-1MN (Genentech) in Combination With QS21 Adjuvant and/or Alum in Healthy Adults.

Inclusion Criteria Subjects must have: * Normal history and physical exam. * HIV negativity by ELISA within 6 weeks of immunization. * CD4 count \>= 400 cells/mm3. * Normal urine dipstick with esterase and nitrite. Exclusion Criteria Co-existing Condition: Subjects with the following symptoms or conditions are excluded: * Hepatitis B surface antigen. * Medical or psychiatric condition or occupational responsibilities that preclude compliance. * Active syphilis. NOTE: Subjects with serology documented to be false positive or due to a remote (\> 6 months) treated infection are eligible. * Active tuberculosis. NOTE: Subjects with a positive PPD and 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, autoimmune disease, or use of immunosuppressive medications. * History of anaphylaxis or other serious adverse reactions to vaccines. * History of allergy to thimerosal. * AS PER AMENDMENT 07/02/97: History of eczema or allergic-type reactions to rsgp120/HIV-1MN vaccine (for volunteers undergoing DTH testing). Prior Medication: Excluded: * Live attenuated vaccines within 60 days prior to study entry. (NOTE: Medically indicated subunit or killed vaccines, such as influenza or pneumococcal, are allowed but should be given at least 2 weeks prior to HIV immunizations.) * Experimental agents within 30 days prior to study entry. * Prior HIV vaccines. * AS PER AMENDMENT 07/02/97: Use of systemic steroids in the past month (for volunteers undergoing DTH testing). Prior Treatment: Excluded: * Receipt of blood products or immunoglobulin within the past 6 months. Identifiable high-risk behavior for HIV infection as determined by screening questionnaire, including history of injection drug use within the past year and higher or intermediate risk sexual behavior.