May 16, 2008
Debunking the Myth 25 Years Later:
An AIDS Vaccine is Possible and Still Urgently Needed
NEW YORK, NY, May 16, 2008 —Twenty-five years since the discovery of HIV, the world has made considerable advances in addressing the AIDS pandemic. Scientists have learned a tremendous amount about HIV, perhaps more than any other pathogen, and have developed more drugs to treat AIDS than all other viral diseases combined. But this progress is not enough. While it is vital to treat as many HIV-infected individuals as possible and provide current prevention options more widely, the world still urgently needs to search for new tools that can prevent people from becoming infected with HIV in the first place. And a vaccine remains the best hope for eliminating this devastating disease once and for all.
Eleven years ago, during a commencement speech made at Morgan State University, U.S. President Bill Clinton called for an AIDS vaccine within a decade. A year later, AIDS vaccine advocates around the world marked the first World AIDS Vaccine Day. While Clinton’s ten-year goal was unfortunately not met, a great deal has been learned in the quest to develop a vaccine.
This has been an eventful year in AIDS vaccine development; the second vaccine candidate to complete efficacy testing failed. In the wake of this news, some skeptics have questioned whether an AIDS vaccine will ever be developed. It is true that scientists have a difficult task ahead, and much remains unknown. But on May 18, as we honor all the individuals who work tirelessly to help make an AIDS vaccine a reality, it is an appropriate moment to reflect on what we do know. It’s much more than many realize.
Science suggests an AIDS vaccine is possible. Nearly every individual who becomes infected with HIV is able to hold the virus in check for several years before progressing to AIDS. What’s more, some individuals, known as elite controllers, are able to hold the virus in check indefinitely. Scientists are now actively studying the immune responses of these unique individuals to identify clues that could help in the design of an effective AIDS vaccine.
Second, some HIV-infected individuals develop antibodies that are capable of neutralizing a broad range of HIV strains. To date, scientists have identified and mapped the structure of several of these antibodies and are actively trying to design immunogens that can stimulate the production of these antibodies in humans.
Finally, non-human primates immunized with a live, but weakened form of the simian equivalent of HIV are protected from infection. For safety reasons, we cannot immunize humans with weakened HIV, but scientists are actively studying the immune responses of these animals to better understand what it is that protects them from infection and to replicate these responses in the next generation of AIDS vaccine candidates.
Developing an AIDS vaccine is pioneering science. Scientists are hard at work on fresh new approaches to AIDS vaccines. Many of the AIDS vaccine candidates in the current pipeline focus on one arm of the immune system, aiming to stimulate T-cell immunity. It is likely that a fully preventive vaccine will need to stimulate both T-cell and antibody immune responses: antibodies to prevent the initial infection and T-cell immunity to mop up any rogue cells that do become infected. AIDS vaccine researchers are focused on both of these approaches, designing new vectors to carry the vaccine inserts, including some that replicate in the mucosal surfaces where HIV often enters the body. Experts are also collaborating worldwide to develop vaccine antigens that elicit broadly neutralizing antibodies and are even testing new technologies that could help to more effectively deliver vaccines. This past year alone, several organizations, including IAVI, have also created financing incentives to encourage biotechnology companies, which often contain a treasure trove of new ideas, to apply their technologies to AIDS vaccine discovery efforts.
Continued clinical research is also critical. We need to learn as much as possible about HIV and human responses to it. How does the immune system initially respond to HIV, and how does the virus change to escape detection from the immune system after it enters the body? What can we learn from the immune responses of newly-infected individuals? The answers to these questions may provide insights critical to the design of future vaccine candidates.
An AIDS vaccine is still urgently needed. Vaccines are one of the most effective public health interventions ever known. History has shown that a vaccine is the only way to eliminate a major viral epidemic. It has also shown that vaccines can take decades to develop. HIV was discovered 25 years ago, but we have only had a concerted AIDS vaccine effort for the last ten years. With nearly 7,000 new HIV infections per day, we must continue to do everything in our power to develop a vaccine that could eliminate the AIDS pandemic once and for all. AIDS remains the fourth-leading cause of death globally and the number one killer in sub-Saharan Africa.
Long-term support is needed. Developing an AIDS vaccine will require sustained commitment from the best minds in science, industry and academia, as well as political and financial support from governments and donors around the world. On May 18, as we honor those who have avidly supported and participated in AIDS vaccine research, we call upon these existing advocates, as well as new ones, to maintain their support for the long haul. Developing an AIDS vaccine isn’t going to be easy. At IAVI, we look forward to a World AIDS Vaccine Day that can be marked with the actual discovery of a vaccine that has stopped the spread of HIV. Until then, we remain committed to accelerating vaccine discovery and development efforts toward that goal.
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