After many frustrating years, AIDS researchers finally have reason to believe that the human immunodeficiency virus (hiv) can be controlled. Several studies reported in 1996 found that a combination of drugs could sharply curtail the amount of virus in the bloodstream--in many cases reducing it to undetectable levels. Since the virus count is the best predictor of how the disease will progress, it now seems that aggressive drug therapy may provide a powerful weapon against aids.