Reports from the 4th Annual Conference on Retroviruses and Opportunistic Infections provided the research results on HIV's slow eradication from the bodies of some patients and the problem of reaching the virus in areas where drugs cannot penetrate. Dr. Ho estimates that HIV treatment must be continued for at least 2.5 years, with HIV completely suppressed the entire time, before cessation of HIV treatment should be considered. However, people with complex treatment histories and problems taking their drugs may have to be treated for decades or for the rest of their lives to keep HIV under control. Treatment outcomes are largely determined by drug resistance and the conference reported mixed news on which drugs might succeed against HIV. Regardless of the long-term complexities, the conference provided evidence of immediate results of the new combination therapies, involving a reduction in hospitalizations or deaths occurring over the past year.