The Mma Bana Study, led by Dr. Roger Shapiro, an infectious disease specialist at the Harvard AIDS Initiative (HAI), compared three different drug regimens to prevent mother-to-child transmission of HIV though pregnancy, delivery and six months of breastfeeding. In following 730 HIV-infected pregnant women in Botswana, the team showed an overall infant HIV infection rate of less than 1%. “This is the lowest rate of mother-to-child transmission ever recorded in a study from Africa or among breastfeeding infants,” said Shapiro. The results from the trial were published in The New England Journal of Medicine this June.
Of the 430,000 HIV infections in children each year, over 90% occur in sub-Saharan Africa. Over 40% of those infections occur during breastfeeding. Without intervention from antiretroviral drugs (ARVs), over 25% of infants born to HIV-positive women will become infected.
Past studies had shown that infant mortality rates were unacceptably high in Botswana and elsewhere in Africa if infants were fed with formula, rather than breast milk. Researchers were trying to determine how infants could best benefit from the immune protection of their mothers’ milk without becoming infected with HIV.
The Mma Bana (meaning “mother baby” in Setswana) Study was conducted at four clinical sites in Botswana as a collaboration between HAI and the Botswana government. The 730 HIV-positive women were given one of three different highly active antiretroviral therapy (HAART) regimens. The women began the drugs at about the third trimester of pregnancy and stayed on them through six months of breastfeeding. Their infants were tested for HIV infection/transmission at several intervals, including at birth and after six months of breastfeeding.
All HAART regimens used in the study were found to be highly effective at suppressing HIV viral load with a 95% viral suppression in the mother at delivery and 93% throughout breastfeeding. Two of the three drug combinations (Combivir/nevirapine and Combivir/Alluvia) gave particularly impressive results—one infant infection in each group during pregnancy and no infections during birth or through breastfeeding. The third combination drug, Trizivir, resulted in three infections during pregnancy and two during breastfeeding. The overall rate of infant infections in the study was 1%.
“Until now HIV-infected mothers in Africa were faced with a choice between breastfeeding and a high risk of infecting their children with HIV, or using formula and risking high infant morbidity and mortality from other diseases associated with not breastfeeding,” said senior author Dr. Max Essex, Chair of HAI. “This study provides a more satisfactory solution.”
The message is clear. Giving mothers HAART from early in the third trimester of pregnancy through six months of breastfeeding is a safe and effective strategy for preventing mother-to-child transmission of HIV while allowing for the benefits of breastfeeding. The Mma Bana findings have already influenced World Health Organization (WHO) policies for areas where formula feeding is neither safe nor feasible.
In an accompanying editorial in The New England Journal of Medicine that discussed recent clinical trials to prevent mother-to-child transmission, Dr. Lynne Mofenson of the National Institutes of Health stated, “We now have the tools to make a considerable difference in controlling the pediatric HIV-1 epidemic. A generation of children awaits our actions.”