To compare the effect of AS-101 to that of placebo on clinical efficacy and immunologic function in HIV positive patients with advanced disease. To compare the effect of AS-101 to that of placebo on occurrence of disease progression in HIV positive patients with advanced disease as defined by: (1) development of new diagnostically confirmed major opportunistic infection(s); or (2) development of AIDS-related dementia. To compare the effect of zidovudine (AZT) plus AS-101 versus AZT alone (placebo arm) on clinical efficacy and immunologic function in patients who require anti-viral therapy due to disease progression. Garlic capsules will be given to all study participants to mask the obvious garlic odor of AS-101.