Appropriate second-line antiretroviral therapy for HIV infection is needed in resource-limited settings. In a comparison of three protease-inhibitor–based regimens in sub-Saharan Africa, the one that included nucleoside reverse-transcriptase inhibitors performed favorably. The public health approach of the World Health Organization (WHO), 1 together with large-scale donor funding, has enabled millions of adults and children in sub-Saharan Africa who are infected with the human immunodeficiency virus (HIV) to have access to lifesaving antiretroviral therapy. 2 The key principle is the use of simplified, standardized approaches that are feasible on a large scale in resource-limited settings, 1 , 3 including a first-line regimen of two nucleoside reverse-transcriptase inhibitors (NRTIs) plus one non-NRTI (NNRTI). In most settings, treatment is monitored clinically and with the use of CD4+ counts, with typically late detection of treatment failure, accompanied by substantial . . .