NIAID Now | January 25, 2019
Previous studies have shown that providing HIV-infected mothers or their uninfected infants with antiretroviral therapy (ART) during breastfeeding is safe and associated with very low transmission of HIV from mother to child for up to 6–12 months of breastfeeding. However, until now, no study has compared these strategies beyond 12 months of breastfeeding. This is important because breastfeeding of HIV-exposed infants beyond the first year of life, particularly in resource-limited settings, is associated with decreased illness and improved survival of the infant.
As part of the NIAID-funded, multinational Promoting Maternal and Infant Survival Everywhere (PROMISE) study, researchers followed 2,431 mother-infant pairs in sub-Saharan Africa and India throughout the duration of breastfeeding and into the second year of the infant’s life. On average, the women in the study did not have symptoms of HIV/AIDS and had relatively high CD4+ cell levels—a marker of good immune system health.
Of the 2,431 mother-infant pairs, 1,220 were randomly assigned to maternal ART, in which the mother received a three-drug ART regimen, and 1,211 were randomly assigned to infant nevirapine, in which the infant received daily doses of the antiretroviral drug nevirapine.
The study found that maternal and infant ART strategies were equally safe and effective at preventing transmission of HIV to the infant for up to 24 months of breastfeeding. Under both treatment strategies, only 0.6% and 0.9% of infants became HIV-infected at 12 and 24 months, respectively, after the baby was born. These results show that while the preferred strategy of treating the mother as part of lifelong ART is highly effective at reducing mother-to-child HIV transmission, infant nevirapine is an effective and safe alternative. This alternative may be needed for infants of mothers who cannot or do not adhere to ART, who temporarily stop ART due to serious side effects, or who have persistent HIV infections that do not respond to ART. However, some of the same barriers may also apply to infant nevirapine.
Reference: Flynn PM et al. Prevention of HIV-1 transmission through breastfeeding: efficacy and safety of maternal antiretroviral therapy versus infant nevirapine prophylaxis for duration of breastfeeding in HIV-1-infected women with high CD4 cell count (IMPAACT PROMISE): a randomized, open-label, clinical trial. J Acquir Immune Defic Syndr. 2018 Apr 1;77(4):383–392.