A team of scientists from the United
States and Uganda reported today that the inexpensive AIDS
drug nevirapine, when given to both mother and child around
the time of birth, greatly reduces mother-to-infant
transmission of HIV up to a year after the medicine was
given. The updated results of the study were presented
today in a session of late-breaking research results at the
13th International AIDS Conference in Durban, South
The latest findings stem from the continued follow-up of
breastfeeding mothers and their babies enrolled in a
clinical trial (HIVNET 012). Last year, results from that trial
(available at www.niaid.nih.gov/cgi-shl/simple/release.cfm) showed
that a short regimen of nevirapine given to both mother and
child significantly reduced HIV transmission. Today's
announcement reported that this reduction in mother-to-
infant transmission of HIV was sustained even though the
infants were breastfed.
Conducted at the teaching hospital of Makerere University in
Kampala, Uganda, the study compared the safety and efficacy
of a short course of nevirapine with that of another AIDS
drug, AZT. One group of women received a single dose of
nevirapine during labor and their infants received one dose
within 72 hours of birth. The second group of women
received AZT during labor while their newborns received
twice daily doses for 7 days. After 6-8 weeks, both
regimens were well tolerated, but mothers and infants who
received nevirapine had a 42 percent lower risk of HIV
transmission when compared with those receiving AZT.
New data on those same infants 12 months later show
nevirapine continues to reduce risk of HIV transmission over
AZT. After 6-8 weeks, nevirapine showed a 42 percent
reduction in HIV transmission compared to AZT. At 12
months, the reduction was 39 percent, and preliminary
results indicate a reduction of 42 percent after 18 months.
In addition, the benefits of nevirapine occurred despite
breastfeeding by the women in the study.
Genetic analysis of HIV in the mothers showed that while a
small number of mutations do occur in the virus that make it
impervious to the drug, those mutations fade from detection
within 13-18 months after delivery. This suggests that
repeat doses of nevirapine given to the mother will continue
to prevent HIV transmission during future pregnancies.
Researchers also assessed how well the amount of HIV and CD4
T-cells in the mother's blood would predict the likelihood
of her passing the virus on to her baby. Women with more
virus and fewer CD4 T-cells in their blood were more likely
to transmit HIV to their offspring than were those with less
virus and more CD4 cells.
Together, these findings further indicate that a short
nevirapine regimen is an effective, simple, and extremely
low cost method for preventing transmission of HIV from
mother to child in developing countries.
The trial was led by Dr. Brooks Jackson at The Johns Hopkins
University and Professor Francis Mmiro at Makerere
University. Statistical analysis was coordinated by Dr. Tom
Fleming at the Fred Hutchinson Cancer Research Center