ORIGINAL DESIGN: Patients are randomized to one of five groups to receive, intramuscularly, one of four dosages of gp160 or hepatitis B vaccine as a control. Treatments are given at 0, 1, 3, 6, 9, and 12 months and patients are followed for up to 2 years. Patients in any of the 5 groups will have the option of switching to another dosage group if an interim analysis at 6 months shows significant differences in patient response. AMENDED: 10/23/90 52 eligible patients are randomized to one of 6 study groups. Five groups of 8 individuals receive one of 4 dosage levels of gp160 (Groups A, B, C1, C2, and D), and 12 patients receive a single dosage level of hepatitis B vaccine as a control (Group E). Per 2/19/92 amendment, patients may elect to continue receiving vaccine beyond 12 months, with the doses given either every 3 months or every 6 months.