Simple, safe, inexpensive nevirapine regimen nearly halves the risk of mother-to- newborn HIV infection
Researchers in the Public Health Sciences Division and an international group of collaborators have published the final results of a study showing that a simple, inexpensive treatment significantly reduces the transmission of the AIDS virus from mothers to babies during childbirth and during the first few weeks of life, offering a good chance to curb the spread of HIV.
A study of more than 600 women in Uganda found that a single dose of the drug nevirapine to HIV-positive mothers during labor and one dose to their newborns reduced viral transmission by 41 percent through age 18 months in comparison to the more costly AZT.
The results extend the group's published report in 1999 that the short-course nevirapine regimen decreased the risk of mother-to-child transmission by 47 percent 14-16 weeks after birth.
Scientists at the Johns Hopkins School of Medicine led the final analysis, published in the Sept. 13 issue of The Lancet. Dr. Thomas Fleming, Martina Deseyve, Dr. Lynda Emel and Anthony Mwatha, all of the Statistical Center for HIV/AIDS Research and Prevention in PHS, were co-authors.
"These results confirm that a simple, safe and convenient intervention can now be made available to substantially reduce the risk of mother-to-child transmission of HIV in resource-limited settings," said Fleming, also chair of the biostatistics department at the University of Washington.
"Our challenge now is to achieve widespread implementation of this prevention regimen in developing countries where the unmet need is greatest," he said.
Worldwide, mother-to-child transmission during gestation, birth or breast feeding infects roughly 800,000 babies each year with the HIV virus, according to UNAIDS and the World Health Organization. More than 90 percent of these babies are in resource-poor countries where treatment of HIV infection is not available to mothers, alternatives to breast milk aren't widely available and strategies used elsewhere to prevent such transmission are prohibitively expensive.
In the study, 308 mothers and their babies received AZT, and 311 pairs of mothers and infants received nevirapine. Women in the AZT group received 600 milligrams when labor began, and additional doses of 300 milligrams every three hours until delivery. Babies in this group received small, twice daily doses of AZT for a week. Women in the nevirapine group received a single 200-milligram dose of the drug at the beginning of labor, and babies received a small dose within three days of birth.
At 6 to 8 weeks of age, 59 babies in the AZT group were HIV positive, while only 36 babies in the nevirapine group were HIV infected. By 18 months of age, 75 babies in the AZT group and 47 in the nevirapine group were HIV positive. Because infant mortality is quite high in less-developed nations, the researchers also analyzed the data using death or HIV infection as the endpoint, and the gap between the nevirapine and AZT groups was still present (63 babies in the nevirapine group and 92 babies in the AZT group at 18 months had died or were HIV positive). Results will be reported again once all babies reach age 5.
The study was funded by the National Institute of Allergy and Infectious Diseases (NIAID) and funded by and conducted through the HIV Prevention Trials Network, which is principally funded by NIAID and?co-sponsored by the National Institute of Child Health and Human Development, the National Institute on Drug Abuse, the National Institute of Mental Health and the National Institutes of Health's Office of AIDS Research. Boehringer-Ingelheim Pharmaceuticals provided nevirapine for the study.
[Adapted from Johns Hopkins School of Medicine news release]