Stage of the epidemic and viral phenotype should influence recommendations regarding mother-to-child transmission of HIV-1

This article argues for a new approach to use of nevirapine in the prevention of vertical transmission of HIV-1. Existing antenatal surveillance should be strengthened to plan geographical allocation, and subsequent evaluation, of a "nevirapine plus" programme. As the epidemic evolves the programme should also and, ideally, care should be tailored to individual women. Underpinning this approach is evidence that a more virulent viral phenotype appears in many patients with advanced HIV-1 infection. This phenotype will become more common at the population level as the epidemic progresses. As efficacy of zidovudine correlates with viral phenotype, and use of the drug may alter phenotype, there is an urgent need for a replacement that is safe to use with nevirapine.