A Phase I Multicenter Study of the Safety and Immunogenicity of MN rgp120/HIV-1 Vaccine Given Either Alone or in Combination With IIIB rgp120/HIV-1 Vaccine in Healthy Adult Subjects (NOTE: Original Study Extended ONLY for Patients Previously Enrolled on VEU 009)

AMENDED 10/1/93: To evaluate the influence of prior immunization with an rgp120 vaccine on immune response to a subsequent immunization with a different strain of rgp120 (VEU 009X extension - in patients previously enrolled on VEU 009). ORIGINAL DESIGN: To evaluate the clinical and immunologic safety of MN rgp120/HIV-1 vaccine (MN rgp120 vaccine) given alone or concurrently with the IIIB rgp120/HIV-1 vaccine (IIIB rgp120 vaccine) in healthy HIV-1 seronegative adult subjects. To compare the immune response to MN rgp120 vaccine given at 100, 300, or 600 mcg. To determine the immune response to 300 mcg MN rgp120 vaccine and 300 mcg IIIB rgp120 vaccine given concurrently. Recent studies suggest that immunity to the HIV-1 rgp120 protein may prevent primary infection. MN rgp120 vaccine and IIIB rgp120 vaccine are both prepared by recombinant DNA technology. Because the two vaccines are derived from distinct HIV-1 strains, they may elicit some immunologic responses that differ. Unlike IIIB rgp120 vaccine, the MN rgp120 vaccine has not yet been evaluated in humans, although it is expected that the MN type will result in similar safety and immunogenicity as the IIIB type.