Microbicides: A Vaginal Gel That Could Prevent HIV
by Stephanie Skoler, MPH, Population Council
I am a study manager of the Population Council’s
microbicides program and on January
19th I kicked off this winter’s SMART University by discussing the
Council’s research
on HIV prevention and, specifically, microbicide development.
Globally, women’s rates of HIV infection are rising higher and faster
than men’s, and the
existing strategies for prevention—abstinence, condom use, and mutual
monogamy
between HIV-negative partners—are not practical for the majority
of women, particularly
those in developing countries.
In March 2004, the Population Council began a large
clinical trial of a potential
microbicide—a vaginal gel called Carraguard® —that may
be able to protect women
from becoming infected with HIV. If proven effective, this colorless,
odorless gel will
offer a powerful new tool against AIDS.
Because of the urgent need for a female-controlled product useful to all
women, the
Council’s first candidate for a microbicide, Carraguard, was designed
so that it does not
prevent pregnancy. However, additional microbicide products the Council
is developing
do include a contraceptive option.
Before the current study was begun, five safety studies
of Carraguard were performed on
seven different continents, with HIV-negative as well as HIV-positive
women and men. It
was important to make sure the gel was safe for HIV-positive people, since
many women
may want to use it to prevent re-infection with a different strain of
HIV and because,
should the gel prove effective, many infected people may use it without
knowing their
own HIV status.
The current Carraguard study is being conducted at
three clinic sites in South Africa in
collaboration with the Medical University of Southern Africa, the University
of Cape
Town, and the Medical Research Council. Altogether, 6,203 HIV-negative,
non-pregnant
volunteers who were able to commit two years to the study were enrolled
and randomly
and anonymously assigned to one of two study groups. Not even the researchers
know
who is in which group, to ensure they do not accidentally cue participants
and affect their
behavior.
One group is using the Carraguard gel, the other a
placebo that smell, tastes, and feels
like Carraguard but contains no active ingredients. Each group is instructed
to use both a
condom—the surest known way to protect against HIV/AIDS—and
a gel during
intercourse. Women in both groups receive benefits, including free pap
smears, condoms,
counseling, and testing for sexually transmitted infections (STIs) and
HIV and AIDS.
Participants with curable STIs are treated, and HIV-positive women are
given additional
counseling sessions and referred to hospital programs.
The study will end on March 31, 2007. After that, the
data will be analyzed and will
reveal to what extent Carraguard protects women from HIV infection. The
gel is not
expected to provide 100 percent protection, but even if it is 50 percent
effective, it could
mean hundreds of thousands, perhaps millions, of HIV infections avoided
and lives
saved.
In addition to the Carraguard study, the Council is carrying out several
other studies in
the three South African clinics: researching the acceptability of the
gel, testing informed-
consent procedures within the trial, and evaluating the HIV and AIDS services
of the
local health care system.
Funding from a dozen major grant-making institutions—in
particular the United States
Agency for International Development (USAID), the Bill and Melinda Gates
Foundation,
and the International Partnership for Microbicides—supports the
work described above.
For more information on the Population Council, you can visit the website
www.popcouncil.org/microbicides.
This spring, The Microbicide Development Act will be
introduced in both the House and
Senate. The goal of the bill will be to achieve better coordination and
expanded resources
for microbicide research and development in the major US government agencies—the
National Institute of Health, the Centers for Disease Control and Prevention,
and USAID.
For more information on how you can support microbicides development and
this bill in
particular, you can visit: www.global-campaign.org.
