In the study presented at the 2008 Conference on Retroviruses and Opportunities Infections in Boston, researchers at The Johns Hopkins University and colleagues in Ethiopia, India and Uganda gave infants aged 8 to 42 days nevirapine once a day. They found that the risk of HIV transmission induced by breastfeeding was halved at 6 weeks of age.
The decrease occurred in comparison to a single dose of nevirapine given to infants at birth, the current standard of care. At 6 months of age, the risk of postnatal HIV infection or death in infants who received the six-week regimen was almost one-third less than the risk for infants given only a single dose.
Breast-feeding causes HIV infection in about 150,000 infants throughout the world each year. Breastfeeding remains a leading cause of HIV transmission in the developing countries. In the United States, fewer than 150 newborns are infected with HIV at birth.
The study, conducted from 2001 to 2007 and involving approximately 2,000 infants, is one of the first randomized controlled trials to show that a drug can prevent HIV transmission to uninfected babies exposed to their infected mothers' breast milk.
According to a press release by the University, the significant part of the results is that now we know that the drug at low dose was able to reduce transmission or death in breast-feeding infants and that the extended-nevirapine regimen seems to be as safe as the single dose treatment.
The study is also significant, the scientists say, because it is the first to show that an antiretroviral drug can prevent HIV transmission through mucosal tissue.
This finding has implications for the potential value of antiretroviral drugs for preventing sexual transmission of HIV, they added.
The study was sponsored by the Division of AIDS at the National Institute of Allergy and Infectious Diseases, one of the National Institutes of Health.