Patients are randomized to receive one of three vaccines (9 patients/vaccine) or the adjuvant placebos (3 patients/vaccine). The vaccines will be studied at both low and high doses. When three of four patients at the low dose of a vaccine have received two immunizations without evidence of dose-limiting toxicity, dose escalation to the higher dose of that vaccine is initiated in subsequent patient cohorts, provided all low dose arms are filled. A total of six immunizations are given, at 0, 4, 8, 12, 16, and 24 weeks. Patients are followed for 24 weeks after the last immunization.