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We performed a retrospective observational study of 253 children vertically infected with human immunodeficiency virus (1994–2001) to assess the effectiveness of antiretroviral therapies (ARTs) on survival and surrogate markers at the population level. Children were divided into 3 groups according to the ART protocols used during the follow-up period: calendar period (CP) 1 (1994–1996) received combined therapy with 2 nucleoside reverse transcriptase inhibitors (NRTIs); CP2 (1997–1998) received implementation of highly active ART (HAART) with 3 drugs (NRTIs, protease inhibitors, and non-NRTIs); and CP3 (1999–2001) received extensive HAART. The children in the CP3 group had statistically significant longer survival periods, lower virus load (VL), highest undetectable VL proportion, and highest CD4+ T cell counts. HAART is effective at the population level at decreasing VL, increasing CD4+ T cells, and increasing the survival in a higher percentage of HIV-infected children.