NOTE B: For the purposes of this protocol, "a change due to virologic failure" is defined as any of the following events or combinations thereof happening in a patient who is receiving uninterrupted combination antiretroviral therapy including at least three agents belonging to at least two classes: a) plasma HIV RNA is >200 copies/mL on two or more consecutive occasions; b) the treating physician determines that any given plasma HIV RNA value is indicative or suggestive of virologic failure, and recommends that the patient's regimen be modified as a result; c) a genotypic or phenotypic antiretroviral resistance test identifies the presence of resistance to any component of a patient's regimen that was not present before, and a physician recommends that the patient's regimen be modified as a result.