[CCIH-AIDS] Washington Post article: Rethinking AIDS Strategy

[Allison Herling Ruark]

*Rethinking AIDS Strategy After a String of Failures*
In Wake of Canceled Vaccine Study, Some Experts Are Reemphasizing Proven,
Low-Tech Prevention Methods

By Craig Timberg
Washington Post Foreign Service
Thursday, November 1, 2007; A12

DURBAN, South Africa<http://www.washingtonpost.com/wp-srv/world/countries/southafrica.html?nav=el>--
Few cases of AIDS have been as closely scrutinized as that of a former
South
African<http://www.washingtonpost.com/ac2/related/topic/South+Africa?tid=informline>prostitute
named Beauty. Scientists know when this 40-year-old woman became
infected, how her body responded and what happened as her immune system
collapsed.

But when the subject turns to how Beauty might have been protected from the
AIDS virus in the first place, scientists have few good leads. This fall,
pharmaceutical giant Merck & Co. halted study of one of the most promising
possibilities, a genetically engineered vaccine being tested on four
continents, because it simply did not work.

After this latest setback, and with billions of dollars spent on research
over more than two decades, scientists say they do not know when -- if ever
-- a vaccine will be available in the fight against one of the world's most
devastating epidemics. The news has been nearly as bad for other
technological solutions, including vaginal microbicides, one-a-day
prevention pills and diaphragms.

"We are really groping in the dark," said Salim S. Abdool Karim, director of
the Center for the AIDS Program of Research in South Africa, in the seaside
city of Durban<http://www.washingtonpost.com/ac2/related/topic/Durban?tid=informline>
.

The recent string of failures has sent scientists back to the lab, where, by
studying the first months of infection in subjects such as Beauty, they hope
to unlock some of the most enduring mysteries of HIV, the virus that causes
AIDS.

But as they do, pressure is building from other experts -- some
epidemiologists, physicians and scientists -- to shift attention away from
technological fixes. They favor devoting more of the world's $10 billion
annual AIDS spending to proven, lower-tech strategies against HIV, such as
circumcising men, promoting sexual monogamy and making birth control more
easily available to infected women.

"It's criminal not to put money into the things that work, and the things
that work are relatively inexpensive," said Malcolm Potts, a professor at
the University of California at
Berkeley<http://www.washingtonpost.com/ac2/related/topic/University+of+California-Berkeley?tid=informline>and
former head of Family Health International, a research group with
extensive experience in fighting AIDS. "We're spending money in the wrong
places."
*A Difficult Target*

Scientists first identified AIDS in 1981. Despite more than 150 trials and
steady flows of cash from the National Institutes of
Health<http://www.washingtonpost.com/ac2/related/topic/National+Institutes+of+Health?tid=informline>,
the Bill and Melinda Gates Foundation and other major donors, there are few
promising vaccine candidates, scientists say. The most anticipated,
developed by NIH scientists, somewhat resembles the Merck vaccine and is due
to enter trials soon.

HIV has proved a difficult target in part because it hijacks the immune
system, turning the body's own defense mechanisms against it. Then the virus
mutates so quickly that a tactic that works one week might be obsolete the
next. Because nobody has ever been able to rid their body entirely of the
virus, scientists say they do not know what a successful immune response
would even look like -- making it harder to know how to provoke one with a
vaccine.

Vaccines for polio, flu and measles are made from dead or weakened viruses.
They generally do not cause disease, instead producing immunities that help
vaccinated people battle the pathogens if encountered later at full
strength.

Because scientists feared that even a dead or weakened version of the AIDS
virus might cause a lethal infection, the Merck vaccine attempted to
stimulate an immune response by altering a common, but much less dangerous,
virus to include genetic elements of HIV. Though researchers did not expect
the vaccine to prevent someone from contracting HIV, they thought it might
prepare the immune system to battle a later infection, helping delay its
progress to full-blown AIDS.

It didn't. The safety monitoring board for the trial called for it to be
stopped Sept. 21 because the vaccine was ineffective.

Here in Durban, one of the most heavily infected cities in the world,
researchers at Abdool Karim's center called each of their 53 vaccine trial
participants with the grim news.

Bonga Mkhize, 24, who had received a shot in his upper arm over the past few
months, said glumly, "I was expecting it to work."

Among a group of nearly 700 subjects worldwide who received two doses of the
vaccine, 19 became infected with HIV, compared with 11 for a similarly sized
group that received placebos. The finding alarmed some scientists and
underscored the tricky ethics of using human subjects to test potential
remedies for incurable diseases.

South African researchers last week began warning hundreds of volunteer test
subjects that the vaccine might actually have increased their risk of
contracting HIV.

Two trials for microbicides -- gels that women insert into their vaginas to
prevent infections -- also ended when more women using the experimental
substance became infected with HIV than those using placebos. Scientists
theorize that vaginal irritation caused by these products may have made it
easier, not harder, for the virus to infect women. A study of whether
diaphragms might inhibit HIV found that they were also ineffective.

"It's been an appalling year for the biologists," said Francois Venter,
president of the Southern African HIV Clinicians Society.
*Technology vs. Reality*

A technology that has worked in highly controlled settings often fails in
the context of actual sexual behavior.

Hospitals routinely use antiretroviral drugs, for example, to prevent
infections in doctors and nurses stuck by HIV-infected needles. But when
researchers asked healthy West African women to take such medicine every
day, the difference in infection rates was so small that scientists could
not determine whether the medicine worked.

Condoms, meanwhile, can block HIV but are not used routinely enough to
reverse the widespread epidemics in sub-Saharan
Africa<http://www.washingtonpost.com/ac2/related/topic/Sub-Saharan+Africa?tid=informline>
.

Researchers have struggled to prove the effectiveness of other popular and
heavily funded strategies. For example, many scientists believe that
treating sexually transmitted infections should slow HIV by healing the
ulcers that encourage infection. But five of six large studies so far have
ended in failure.

Theories about the ability of HIV testing and counseling to encourage safer
sexual behavior also remain unproved. In some studies, those who learned
they had the virus reported altering their behavior; those who discovered
they were not yet infected did not. But most studies have found that making
HIV testing more available does not slow the spread of the virus, and a
rigorous new one published recently in the publication JAIDS found the virus
spread most swiftly among those with the greatest access to testing and
counseling.

For a study of people at high risk for HIV, Beauty came each month to a
clinic that had muffins and hot tea at the ready. Researchers tested her for
HIV and gave her free condoms, extensive AIDS counseling and a modest
stipend.

Yet when one of her regular customers -- a truck driver who paid about $35
per visit, four times the going rate -- insisted on not using condoms, she
chose to risk contracting a lethal disease.

"I heard about it, but I didn't think it would happen," she said. "Your
heart just tells you, you won't get it."

The unpredictable nature of human behavior helps explain the enduring allure
of a vaccine. If one could be found, a single needle stick -- or maybe two
or three -- would confer a degree of lifetime protection.

"Without a biomedical instrument to prevent HIV, basically the world will
never be able to control HIV because people will never stop having sex,"
said Glenda Gray, the lead South African researcher on the Merck vaccine
trial.
*New Push in Old Direction*

As efforts to find a vaccine or other new technological tool against AIDS
have faltered, the science behind several existing but lower-tech approaches
has grown stronger.

Three studies in three African countries have found that circumcising men
lowers their chance of contracting HIV by about 60 percent. And like a
vaccine, circumcision offers lifelong protection.

Research shows that public campaigns encouraging monogamy also helped reduce
the pace of new infections in
Uganda<http://www.washingtonpost.com/ac2/related/topic/Uganda?tid=informline>,
Kenya <http://www.washingtonpost.com/ac2/related/topic/Kenya?tid=informline>and
perhaps
Zimbabwe<http://www.washingtonpost.com/ac2/related/topic/Zimbabwe?tid=informline>.
In each nation, falling rates of multiple sexual relationships led to
declines in HIV infection rates.

Numerous studies have demonstrated that making birth control easily
available to women with HIV gives them the power to keep from having babies
who might contract the virus. Providing antiretroviral drugs to pregnant
women also limits transmission to babies, but the medicine now reaches only
one in 10 African women who need it.

These approaches do not attract the money or attention enjoyed by potential
technological fixes such as vaccines or microbicides.

A recent U.N.<http://www.washingtonpost.com/ac2/related/topic/United+Nations?tid=informline>report
calling for massive new spending on AIDS projected only about 1
percent of the money funding either circumcision or efforts to change sexual
behavior. There was no line item for expanding access to contraception.

Potts, the Berkeley<http://www.washingtonpost.com/ac2/related/topic/Berkeley?tid=informline>professor,
said the time has come to shift priorities toward existing
strategies, however imperfect.

"If we're defeated in one area, we pull our troops back and attack somewhere
else. That's what we're failing to do," he said. "We need a military
response, and we have a bureaucratic response."


-- 
Allison Herling Ruark, MSPH
Research Fellow
AIDS Prevention Research Project
Harvard Center for Population and Development Studies
9 Bow St., Cambridge, MA 02138
Tel: (617) 495-3639
Email: allison_herling at harvard.edu
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