An antiretroviral drug already in widespread use in
the developing world to prevent the
transmission of HIV from infected mothers to their newborns
during childbirth has also been found to
substantially cut the risk of subsequent HIV transmission
In a study presented Feb. 4 at the 2008 Conference on
Retroviruses and Opportunistic
Infections in Boston, an international team of AIDS experts
reports that nevirapine given once daily
to breast-feeding infants from 8 to 42 days old decreased
by almost half the rate of HIV
transmission via breast-feeding 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. The study was
led by three teams of
investigators at Johns Hopkins in collaboration with
investigators in Ethiopia, India and Uganda.
Breast-feeding remains a leading route of HIV
transmission in the developing world. The World
Health Organization estimates that approximately 150,000
infants are infected through breast-
feeding each year. In the United States each year, fewer
than 150 newborns are infected with HIV at
birth, mostly to mothers who did not know they were HIV
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 the Johns Hopkins scientists, the results
are highly significant because the low-dose regimen of
nevirapine was able to reduce transmission or death in
breast-feeding infants. They
note that the extended nevirapine regimen appears to be as
safe as the single-dose regimen.
The study is also significant, the scientists say,
because it is the first to show that an
antiretroviral drug can prevent HIV transmission through
This finding has implications for the potential value
of antiretroviral drugs for preventing
sexual transmission of HIV.
The six-week extended nevirapine trial, or SWEN study,
included more than 200 scientists and
staff collaborating in many countries. The project was
directed by Johns Hopkins investigators J.
Brooks Jackson and Laura Guay, with colleagues at the
Makerere University/Johns Hopkins University
Research Collaboration in Kampala, Uganda; Andrea Ruff,
with colleagues at Addis Ababa University in
Addis Ababa, Ethiopia; and Robert Bollinger, with
colleagues at BJ Medical College in Pune, India.
Lawrence Moulton, also of Johns Hopkins, was principal
statistician for the study.
The SWEN study was funded by the Division of AIDS at
the National Institute of Allergy and
Infectious Diseases, one of the National Institutes of
Health. Nevirapine is manufactured by the
German pharmaceutical company Boehringer Ingelheim and sold
under the brand name Viramune.