EARLY INTERVENTION may harm African Americans infected with the human immunodeficiency virus (HIV), according to a "fragile" new finding. The data, which come from a post hoc subset analysis not in the study's original design, "may be artifactual and not truly result from a biological effect," cautions John D. Hamilton, MD, cochair of the study and chief of infectious disease at the Durham (NC) Veterans Affairs (VA) Medical Center. Progression to acquired immunodeficiency syndrome (AIDS) and death was higher in blacks given zidovudine (Retrovir [commonly called AZT], Burroughs Wellcome Co) when their CD4 counts were between 200 and 500 mm3than in patients who were not given the drug until their CD4 counts dropped below 200 mm3. Blacks also did not have the "highly significant" CD4 count rise seen in whites when zidovudine therapy is begun, says Hamilton. He presented the findings from the 4-year study, in which