ARM F: GM-CSF daily for 2 weeks, then thrice weekly (MWF). ARM G: IL-12 twice weekly. ARM H: No immune modulation. Patients may be hospitalized to initiate immune modulation or may be treated as outpatients. Immune modulation is discontinued after Week 14. Patients maintain their 4-drug regimen through Week 48. [AS PER AMENDMENT 6/11/99: The study duration has been extended to 96 weeks.] Hepatitis A vaccine (inactivated) is administered on Weeks 16 and 40 [AS PER AMENDMENT 2/13/98: to patients whose baseline hepatitis A serology was negative].