Resetting Expectations in the Search for an AIDS Vaccine

In its AIDS Vaccine Blueprint 2008, IAVI proposes a series of
interim milestones to help overcome the biggest challenges facing the
AIDS vaccine field today
MEXICO CITY--(Business Wire)--
With the release of its AIDS Vaccine Blueprint 2008 at the
International AIDS Conference today in Mexico City, the International
AIDS Vaccine Initiative (IAVI) sought to reset both expectations and
focus in the search for an AIDS vaccine.

"The quest to develop an AIDS vaccine is at a pivotal moment. In
the wake of the failure of a leading AIDS vaccine candidate nearly a
year ago, some have questioned whether we will ever have an AIDS
vaccine," said Dr. Seth Berkley, President and CEO of IAVI. "To these
skeptics, I say that developing an AIDS vaccine may take more time and
innovation than we might have once imagined, but we are confident that
science will prevail. The necessary direction for the field is clear,
and we must march forward. Future generations are counting on us to
bring this epidemic to an end."

IAVI's Blueprint aims to set the record straight about the current
state of AIDS vaccine research and development and offers a series of
interim goals to bring the field closer to the ultimate goal -- a
safe, effective and accessible AIDS vaccine. It proposes progress be
measured against these shorter-term scientific milestones.

"Twenty-five years since the discovery of HIV as the cause of
AIDS, nearly 7,500 people continue to become infected with HIV each
day," said Dr. Peter Piot, Executive Director of the Joint United
Nations Programme on HIV/AIDS. "I am encouraged and inspired to see
that IAVI's AIDS Vaccine Blueprint proposes a well-defined roadmap to
accelerate the development of a critical tool for the elimination of
this terrible disease."

The Blueprint acknowledges that much work remains to be done
before an AIDS vaccine will be in hand, but details the considerable
advances that have been made and the exciting prospects ahead. The
document notes that this base of science forms the foundation for the
considerable work that is going forward.

"Strong scientific evidence in both humans and animal models
suggests that developing an AIDS vaccine is possible," said Dr. Wayne
Koff, Senior Vice President of Research and Development at IAVI. "The
challenge we face now is how to translate advances made in our
understanding of the virus and the human immune responses to it into
promising vaccine candidates as quickly and safely as possible."

"The HIV vaccine research field is at a crossroads. Now is the
time to integrate new ideas and new technologies from other areas of
biomedical research, to energize the field with a new generation of
researchers and to undertake an ambitious program of research aimed at
understanding the full complexity of the human immune response to
HIV," said Dr. Alan Bernstein, Executive Director of the Global HIV
Vaccine Enterprise. "IAVI's Blueprint lays out a clear and realistic
roadmap, with intermediate milestones, of important aspects of where
the field needs to go over the next few years."

IAVI has prioritized the following Blueprint recommendations:

-- Solve the Neutralizing Antibody Problem: Most vaccines work by
neutralizing the virus with antibodies before an individual
can become infected with a pathogen. An AIDS vaccine is likely
to be no exception. To date, researchers have identified
neutralizing antibodies against HIV. They are now trying to
figure out how to design immunogens that generate similar
antibodies. To speed the discovery of an immunogen that can
neutralize a substantial proportion of circulating HIV
strains, existing programs focused on the neutralizing
antibody problem should be scaled up.

-- Solve the Cell Mediated Immunity (CMI) Problem: One of the
lessons of the Merck trial is that inducing effective CMI
responses will be more challenging than originally envisioned
and may be as challenging as solving the neutralizing antibody
problem. We do know, however, that there are rare individuals,
known as elite controllers, who are infected with HIV, but are
able to keep the virus in check for decades without any sign
of disease. What's more, non-human primates vaccinated with a
live, but weakened form of the simian equivalent of HIV (known
as SIV) mount an immune response that protects them from SIV
disease. More resources should be devoted to studying the
mechanisms behind both of these phenomena, which could provide
vital clues for improved vaccine design.

-- Trim and Improve the Pipeline: Current and future AIDS vaccine
candidates need to be compared and prioritized in comparison
to tested vaccines. Those vaccines that cannot demonstrate
superiority should be dropped. Resources from these candidates
should be freed and re-directed towards solving the key
scientific problems currently impeding the development of the
next generation of AIDS vaccine candidates. Those candidates
that do meet pre-defined, mutually-agreed upon criteria, on
the other hand, should be tested in rapid, small
test-of-concept trials before they are moved into conventional
large scale efficacy trials.

To improve the pipeline, IAVI also recommends accelerating the
development of replicating vector-based vaccines. It is likely that
the impressive level of protection afforded by live-attenuated SIV in
non-human primates is at least partially due to its replicative
nature. Because of the novel regulatory and risk-benefit questions
that these vectors will likely raise, replicating vectors have
received little attention to date.

-- Sustain the Effort: The development of an AIDS vaccine
continues to be one the greatest needs of the 21st century and
one of science's greatest challenges. Ensuring adequate
clinical trial and human capacity, providing incentives for
innovation, training the next generation of researchers and
securing long term stable and flexible funding are all
necessary for success.

"Developing a preventive HIV/AIDS vaccine is going to be much
tougher than we originally thought. And we need as many people as
possible committed to helping us reach this goal. The world is now
relying on the talents, resources and energy of researchers, donors,
policymakers, activists and other stakeholders from both the developed
and the developing world to help sustain this vital effort," said Dr.
Omu Anzala, Associate Professor at the University of Nairobi School of
Medicine and Director of the Kenya AIDS Vaccine Initiative.

"We've come a long way in AIDS vaccine discovery and development,
but recognize that there's a long road ahead and there will be further
bumps on that road. IAVI's Blueprint is intended to stimulate debate
within the field that we hope will generate consensus on the most
promising way forward," said Berkley. "We at IAVI will keep using
speed, flexibility and focus to drive forward AIDS vaccine science and
testing, and to keep an AIDS vaccine on the center stage as a
long-term solution to this devastating public health problem."

A recording of the press conference will be available online later
in the day at www.iavi.org/pressbriefing.

About IAVI

The International AIDS Vaccine Initiative (IAVI) is a global
not-for-profit organization whose mission is to ensure the development
of safe, effective, accessible, preventive HIV vaccines for use
throughout the world. Founded in 1996 and operational in 24 countries,
IAVI and its network of collaborators research and develop vaccine
candidates. IAVI's financial and in-kind supporters include the Alfred
P. Sloan Foundation, the Bill & Melinda Gates Foundation, the
Foundation for the National Institutes of Health, The John D. Evans
Foundation, The New York Community Trust, the James B. Pendleton
Charitable Trust, The Rockefeller Foundation, The William and Flora
Hewlett Foundation; the Governments of Canada, Denmark, Ireland, The
Netherlands, Norway, Spain, Sweden, the United Kingdom, and the United
States, the Basque Autonomous Government as well as the European
Union; multilateral organizations such as The World Bank; corporate
donors including BD (Becton, Dickinson & Co.), Bristol-Myers Squibb,
Continental Airlines, Google Inc., Henry Schein, Inc., Merck & Co.,
Inc. and Pfizer Inc; leading AIDS charities such as Broadway
Cares/Equity Fights AIDS and Until There's A Cure Foundation; other
private donors such as The Haas Trusts; and many generous individuals
from around the world. For more information, see www.iavi.org.

International AIDS Vaccine Initiative
Rachel Steinhardt, +1 212-847-1045
Cell: +1 646-578-1672
Director, Global Communications
rsteinhardt@iavi.org

Copyright Business Wire 2008