A Phase I, Multicenter, Randomized Trial to Evaluate the Safety and Immunogenicity of Vaccinia-Derived MN HIV-1 Recombinant Envelope Glycoprotein (rgp160) of Human Immunodeficiency Virus at Two Different Vaccination Schedules

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.