Although breastfeeding by HIV-positive women is discouraged in resource-rich countries, it has been shown to protect infants from death in poorer countries. Without the protective elements in mother's milk, these infants have a higher risk of dying from unsafe water and lack of health care or other sanitation. The question then becomes how to protect the child from becoming HIV-infected while breastfeeding.

Researchers pooled the results of five randomized studies using the HIV drug nevirapine to prevent transmission in breastfed infants. Overall, there was a 71% risk of getting HIV in infants given nevirapine. Some of the infants were given nevirapine along with zidovudine (AZT, brand name Retrovir). In the U.S., nevirapine is sold under the brand name Viramune.

Abstract WELBC03 was presented by Dr. Charles Van der Horst of the University of North Carolina, Chapel Hill. Longer duration of nevirapine use was associated with a greater reduction in risk of HIV infection. The data was taken from 5,396 mother-infant pairs in which the infant was HIV-negative at birth.

Two years ago, the World Health Organization (WHO) added the use of HIV medications to prevent mother-to-child transmission during breastfeeding, in the latest update of its treatment guidelines, based on the most current data at that time.