The strongest predictors of progression by 18 months are the presence of moderate clinical symptoms and elevated RNA copy number in the infants in the first 6 months of life. In contrast, progression by 6 months is associated with maternal and infant immun

The findings of a recent human immunodeficiency (HIV‐1) prevention trial in the USA demonstrated that administration of an antiretriviral drug, zidovudine, to mothers during the prenatal and intrapartum periods, and to their neonates for 6 weeks, resulted in a two‐thirds reduction in risk of perinatal transmission from 25.5% to 8.3%. These results were rapidly disseminated both in the USA and internationally. Since the release of these clinical trial results in the spring of 1994, several observational studies have documented a sharp increase in maternal and neonatal zidovudine use, as well as a significant decrease in perinatal HIV‐1 transmission, with rates of about 8% being observed in non‐clinical trial settings. Internationally, the results have led to the development of a variety of perinatal prevention trials that build on the success of the U.S. perinatal prevention trial but use modified strategies that can feasibly be carried out in developing countries.