Researchers at Duke University Medical Center isolated the antibodies from immune cells called B cells in the breast milk of infected mothers in Malawi, and showed that the B cells in breast milk can generate neutralizing antibodies that may inhibit the virus that causes AIDS.

HIV-1 can be transmitted from mother to child via breastfeeding, posing a challenge for safe infant feeding practices in areas of high HIV-1 prevalence. But only one in 10 HIV-infected nursing mothers is known to pass the virus to their infants.

"That is remarkable, because nursing children are exposed multiple times each day during their first year of life," said senior author Sallie Permar, M.D., Ph.D., an assistant professor of pediatrics and infectious diseases at Duke. "We are asking if there is an immune response that protects 90 percent of infants, and could we harness that response to develop immune system prophylaxis (protection) during breastfeeding for mothers infected with HIV-1.