Drug reduces HIV risk for breastfeeding infants

In some parts of the world, mothers are often forced to choose between nourishing or infecting their babies

The Hutchinson Center collaborates in cutting-edge research that saves lives around the world

By Colleen Steelquist, Hutchinson Center science editor

With “cancer research” in our name, some folks aren’t as familiar with the rest of our mission: to prevent, diagnose and treat HIV/AIDS and other diseases. There are many researchers at the Center collaborating with an international team of scientists and educators in the search for a safe and effective vaccine against HIV. This globe-spanning team conducts clinical trials throughout the world of more than a dozen potential vaccines. We’re also helping to implement prevention strategies for HIV and other infectious diseases like malaria.

Important news emerged recently in this area of our research. New preliminary clinical trial results showed giving breastfeeding infants of HIV-infected mothers a daily dose of the antiretroviral drug nevirapine for six months halved the risk of HIV transmission to the infants at age 6 months compared with giving infants the drug daily for only six weeks.

Dr. Deborah Donnell, principal investigator of the HIV Prevention Trials Network, and Dr. Elizabeth Brown, both of VIDD, are the study’s key statisticians.

The study, led by Dr. Hoosen Coovadia of the University of the Witwatersrand in Durban, South Africa, involves more than 1,500 mother-infant pairs in South Africa, Tanzania, Uganda and Zimbabwe. It began in February 2007 and concludes in July 2011. Drs. Deborah Donnell and Elizabeth Brown from the Hutchinson Center are the study’s key statisticians and our Statistical Center for HIV/AIDS Research & Prevention serves as the trial’s data management center.

Encouragingly, the data showed the longer nevirapine regimen achieved a 75 percent reduction in HIV transmission risk through breast milk for the infants of HIV-infected mothers with higher T-cell counts who had not yet begun treatment for HIV.

Since the onset of the AIDS epidemic, the question of whether to breastfeed has posed a conundrum for HIV-positive mothers in developing countries. Extended breastfeeding reduces infant mortality in places that lack safe, clean water by protecting babies from common childhood diseases because breast milk contains protective antibodies from the mother that formula feeding does not provide. But breastfeeding can also transmit HIV.

These findings show that giving the infants of HIV-infected mothers an antiretroviral drug daily for the full duration of breastfeeding safely minimizes the threat of HIV transmission through breast milk while preserving the health benefits of extended breastfeeding.

Mothers with HIV in developed nations like the U.S. are advised not to breastfeed whenever the use of formula is acceptable, feasible, affordable, sustainable and safe.

However, in many resource-poor countries, the risk of life-threatening conditions from formula feeding may be higher than the risk from breastfeeding. In addition to not having the health benefits of breast milk, the cost of infant formula often puts it beyond the reach of poor families in developing nations, even if the product is widely available. Many women also lack access to the knowledge, potable water and fuel needed to prepare formula safely. If used incorrectly—mixed with unsafe water, for example, or over-diluted—formula can cause infections, malnutrition and even death. And if a mother chooses not to breastfeed in countries where it is the norm, this may draw attention to her HIV status and invite discrimination, violence or abandonment by her family and community. Another factor worth noting is the contraceptive effect of breastfeeding, which can help to lengthen the interval between pregnancies.

The participating infants received daily nevirapine for the first six weeks after birth. Those infants who remained free of HIV then were assigned at random to receive either daily nevirapine or a placebo until six months after birth or the cessation of breastfeeding, whichever came first.

The results of this National Institutes of Health-funded study will be very useful to the governments of developing nations when formulating HIV treatment and prevention policies.

There are, of course, no quick or easy answers to the AIDS crisis. But research like this helps not only government policy-makers, but poor mothers who face dire choices between feeding and infecting their infants. In places like Africa, where mother-to-child transmission of AIDS is beginning to reverse decades of steady progress in child survival, it offers hope.