By Richard A. Knox, The Boston Globe
For just $3.67, the chances that an infected mother will pass
the AIDS virus to her newborn can be cut by at least half,
according to a new study with profound implications for the
developing world, where up to 50 percent of pregnant women in some
regions carry the virus.
Specialists said the low cost puts an effective AIDS prevention
tool within reach of poor countries like Uganda, where the study
was conducted with $2 million in US funds. Previous anti-AIDS drug
regimens for pregnant women cost from 14 to 200 times more.
Equally important, researchers said, is the new regimen's
simplicity. In contrast to existing drug treatments that must be
given twice daily for weeks or months, the new therapy involves
giving a single oral dose of an antiviral drug called nevirapine to
women in labor -- the first time in pregnancy that many women in
poor countries see a health professional.
Within three days of birth, her infant gets a single oral dose
of the drug. An added bonus is that the drug doesn't require
refrigeration.
``We probably have 800,000 or even a million infected kids being
born ever year,'' said Dr. Brooks Jackson of Johns Hopkins
University, who led the Uganda study. ``If this regimen could be
used worldwide, that's up to 500,000 lives saved a year.''
Crispus Kiyonga, Uganda's health minister, said the results
``provide real hope that we may be able to protect many of Africa's
next generation from the ravages of AIDS.''
Dr. John Sullivan of the University of Massachusetts Medical
School, who first suggested nevirapine's use to prevent
mother-infant transmission in 1992, predicted the regimen will be
``one of the most important breakthroughs since the AIDS virus was
isolated.
``It's the first bit of hope for the developing world,''
Sullivan added. ``And that's what we need -- the sense that, God,
maybe we do have the chance to beat this virus.''
AIDS Action, a Washington-based advocacy group, called the
low-cost treatment ``the most significant medical breakthrough in
AIDS since the protease drugs,'' a class of pharmaceuticals that
has transformed AIDS in developed nations into a largely treatable
disease since 1996.
Jackson said the majority of Ugandans ``can afford this regimen,
even if they had to pay for it themselves.''
Still, Sullivan and others called on UNAIDS, the United Nations
AIDS agency, as well as the US government and the World Bank to
make large quantities of nevirapine available without cost to the
poorest nations with the highest AIDS rates.
``This means that all the concern about developing countries not
having the resources to prevent mother-child transmission has to be
reexamined in light of what we now know,'' said Dr. Anthony S.
Fauci, director of the National Institute of Allergy and Infectious
Disease, which funded the Uganda study.
One UNAIDS official said Wednesday that the US government has
invested only about $700,000 in a $10 million pilot project to make
a different and more costly drug treatment available to 30,000
pregnant women in Africa and Asia.
That project is using a three-week course of AZT, the standard
AIDS drug for pregnant women -- shorter than the $700 therapy widely
used in the United States and other developed countries, but longer
and more complex than the new regimen.
This ``short course'' AZT treatment has been controversial in
South Africa and other nations, where health officials have
complained that it consumes too many scarce resources.
Nevirapine, a chemical cousin of the tranquilizer Valium, has
the advantage, scientists said, of staying in the bloodstream and
other tissues for days, allowing it to be given as a single dose.
It also has a potent and immediate antiviral effect, attacking AIDS
virus particles floating in the bloodstream as well as those inside
cells. Unfortunately, it cannot be given alone for long periods
without engendering resistance by the virus, erasing the drug's
effect.
Among 310 Ugandan woman and infants who received nevirapine, the
babies' HIV infection rate was 11.9 percent six to eight weeks
after birth, and only about one percentage point higher at 14 to 16
weeks after birth.
Jackson said the fact that the rate did not rise more sharply
with time is encouraging, since virtually all the women in the
study breast-fed their infants. The stable rate suggests, he said,
that nevirapine protected to some degree against HIV's transmission
through breast milk immediately after birth, when the milk has an
especially high level of AIDS virus.
A comparison group of 308 women was treated during labor with
AZT, followed by a week of twice-daily AZT for the newborns. The
infection rate in these babies was 21.3 percent at six to eight
weeks and 25.1 percent at 14 to 16 weeks.
For ethical reasons, the Uganda study did not include a group of
women and infants who received a placebo, or inert pill. But
studies in Uganda and other developing countries have found
infection rates of 17 to 28 percent among babies in such
no-treatment groups.
Thus, the 12 percent viral transmission rate in the
nevirapine-treated infants was 30 to 57 percent lower than babies
without the benefit of some anti-AIDS drug treatment.
``These data are very, very encouraging,'' said Dr. Isabelle De
Vincenzi of UNAIDS, who is overseeing the 30,000-woman AZT project.
``It seems as if this new regimen is as effective as one-month
zidovudine and probably will be cheaper. But we need to be a bit
cautious to see the longer-term followup. And we need to look at
situations where women breastfeed for six months or one year.''
Since nevirapine seems to cause few if any toxic effects, and is
so cheap, some scientists hope it could be given routinely to
pregnant women in regions where HIV infection rates are high,
without the prior expense of blood tests to learn which women are
infected and counseling to help infected women deal with the news.
If such a no-testing strategy is deemed ethical, it may further
lower the cost of delivering nevirapine to high-risk women and
infants.
