CD4 and AIDS: Recent literature indicates that early initiation of HAART may be both effective and cost-effective in preventing and treating HIV.[4]–[6], [12]–[16] In December, 2009 the Department of Health and Human Services Panel on Antiretroviral Guidelines recommended antiretroviral therapy for patients with CD4 counts up to 500 cells/μL, and half the panel recommended starting therapy at higher CD4 counts.[6] These recommendations were based on a reduction in AIDS-related mortality from earlier initiation of HAART found in observational research studies.