The PROMISE trial was conducted at 14 sites in
seven countries (India, Malawi, South Africa,
Tanzania, Uganda, Zambia, and Zimbabwe).
When enrollment began in 2011, standard prevention of mother-to-child transmission for
women with a CD4 count of more than 350 cells
per cubic millimeter in these countries was zidovudine with intrapartum single-dose nevirapine and
a 1-to-2-week “tail” of two nucleosides to prevent
maternal nevirapine resistance.6