Eight patients are entered in the pilot portion of the study, thirty patients are entered on Part A and fifteen patients are entered on Part B. In the pilot study, patients receive 30 mcg Env 2-3 vaccine plus 0 - 10 mcg MTP-PE/MF59 adjuvant. Patients on Part A receive one of the following: MF59 emulsion only; 100 mcg MTP-PE/MF59 only; 30 mcg Env 2-3 with MF59 emulsion only; or 30 mcg Env 2-3 vaccine with 100 mcg MTP-PE/MF59. Patients on Part B receive either 100 mcg MTP-PE/MF59 only or 30 mcg Env 2-3 vaccine plus 100 mcg MTP-PE/MF59. Treatment is administered on days 0, 28, and 112, and patients are followed for up to 10 months. Per amendment, patients may receive two additional doses of 30 mcg Env 2-3 or placebo in MTP-PE/MF59 at 7 and 10 months (Parts A and B) or 9 and 12 months (Pilot study) after their initial inoculation.