HIV/AIDS
Prevention: The Key to Turn the Tide Needs Galvanized Innovations
SCOTT
C. RATZAN
The largest HIV/AIDS
conference in history was convened in Toronto in August, 2006.Following
the United Nations Summit in June where world leaders proclaimed an
‘‘unprecedented human catastrophe,’ the epidemic continues
to grow with new cases outpacing treatment.Currently, 40 million HIV
positive people live while over 5 million annually (14,000 =day) are
infected with HIV. Condoms and counseling have not been enough –the
virus spreads to 5 million more people worldwide each year.
Nonetheless, over
20,000 AIDS researchers, campaigners, patients joined govern- ments,
NGOs and the private sector to further explore mechanisms to address
this major health threat in countries around the world that has already
killed 25 million people. The theme for the 16th conference on HIV is
‘‘Time to Deliver.’’ Recalling the ‘‘successful’’
AIDS conference in Canada in 1996, when HAART was introduced to revolutionalize
AIDS treatment, this year ’s conference is looking for fresh hope
with new means of prevention, expansion of treatment as an outright
cure or vaccine is not in sight. The ‘‘promised’’
vaccine still may be a decade away fromdelivery. To stem the tide of
the epidemic, the only means to combat the disease, is to advance prevention.
In 2004, the Global
HIV Prevention Working Group, a panel of nearly 50 international experts
in HIV prevention, stressed a major shift in HIV prevention as a means
to avoid a rise in HIV transmission and acceleration of the epidemic.
Yet, the political reality for addressing prevention has been limited.
Unless the incidence of HIV infection is sharply reduced, treatment
will not be able to keep pace with all those who will need therapy.
Hence, experts warn that integration of prevention and treatment strategies
must take place. The Group called for annual funding for HIV prevention
and care to increase from $4.7 billion in 2003 to $10.5 billion in 2005
and $15 billion in 2007, as recommended by UNAIDS.
It is time to address
the prevention programs shortfall (e.g., ABC)and enhance programs that
principally address knowledge, personal risk perception and self-efficacy,
behavior change, gender inequalities and social norms. An additional
investment should be made;scientific innovation and intervention has
untapped promise for prevention. The greatest success in treating HIV
has been the medical progress in developing effective ARVs for those
infected. Vaccine research has been challenged, despite the financial
investment and continued announcements of ‘‘within a decade.
’’Microbicides are showing promise, but will present challenges
for large scale prevention.
Early scientific
evidence suggests that the idea of pre-exposure prophylaxis —a
quasi-vaccine to prevent HIV infection —has great promise for addressing
the growing incidence. One of the initial successes presented in Toronto
was such an idea where an antiretroviral medicine was given to HIV negative
women to prevent disease. While the result were preliminary with limited
participants due to the ethical challenges, Dr. Helene Gayle, president
of the antipoverty group CARE and co-chair of the International AIDS
Conference in Toronto, suggested such an approach is ‘‘incredibly
encouraging, ’’as a drug‘‘ would be an incredibly
important new prevention tool that we should make available as soon
as possible. ’’Bill and Melinda Gates both called and offered
financial incentives to help develop or an oral prevention drug for
HIV.
In the absence of
a safe and effective HIV vaccine or universally used microbi- cide or
barrier device, such pre-exposure prophylaxis measures such oral drugs
or injectables warrant exploration. A scientific rationale exists to
consider use of cur- rent therapeutic antiretrovirals as agents to prevent
or lessen the risk of primary infection. Much of the current supportive
evidence comes from post-exposure prophylaxis data. The approach of
using combination antiretroviral therapy following a high risk exposure
to an HIV-infected individual, post-exposure prophylaxis is well accepted.
This approach is supported by both animal and human studies. Additionally,
the use of current antiretrovirals has been successful in decreasing
the risk of mother to child transmission of HIV and is now considered
standard of care.
The accumulated
data suggests that current antiretroviral agents can decrease HIV transmission
and should be explored for pre-exposure prophylaxis in individuals at
high risk for infection or those that would not use other prevention
meth- ods. Of course, this strategy requires that the drugs used for
this purpose are safe and effective, which would need to be demonstrated
in clinical trials. The benefit/risk balance for this approach also
must be favorable, both on an individual and population level for this
to be an acceptable strategy. Antiretrovirals which have a long elimination
half life, and which are safe and convenient would be best suited for
this application. Additionally, other drugs from classes which are under
development, such as various entry inhibitors, may also be good candidates
based on their mechanism of action;however, this remains to be proven
to date.
Ideally, ethical
challenges of conducting such trials with hopeful prospects will be
advanced by donors and related organizations that can help extrapolate
beneficence from a cohort to the millions infected annually. A new initiative
should begin to challenge the biomedical community to explore and develop
an ARV formulation to prevent HIV infection. The ultimate goal of this
challenge would be for the private sector to develop and test a formulation
(e. g. ARVs in oral or long acting form)that would provide protection
from HIV infection. Ideally, with the appropriate coalition this would
be expedited and supported for developing a non-profit partnership that
would foster, facilitate and support clinical trials in resource poor
settings where HIV continues unabated. It would be realistic to envision
that development and clinical trials could be conducted concurrently
while the business framework for bringing this to scale is finalized.
The goal would be that in subsequent HIV confer- ences, this pre-exposure
prevention/prophylaxis would become a new weapon against HIV. Additionally,
through the design it should foster implementing capacity for HIV prevention
and treatment with devolution to developing country institutions who
would engage in the research and distribution.
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Scott C. Ratzan MD, MPA, MA is Editor-in-Chief of the Journal of
Health Communication: International Perspectives. He also is Vice
President, Government Affairs, Europe for Johnson & Johnson with
academic appointments at George Washington University School of Public
Health, Tufts University School of Medicine, Yale University School
of Medicine, The College of Europe, and University of Cambridge.
