World AIDS Day: A Vaccine in the Future?
A few years ago, President Clinton predicted that there would be an AIDS vaccine by 2007. Is this effort on course?
During a commencement address in 1997, President Clinton called on the nation to commit to finding a vaccine against AIDS within ten years. While we're not nearly there yet, it isn't from lack of trying. Since the first HIV vaccine trial started in 1987, more than 40 different preventive vaccines have been studied in clinical trials worldwide. And according to the National Institute of Allergy and Infectious Diseases (NIAID), the government agency coordinating AIDS research, some 3,200 volunteers have enrolled in 52 NIAID-supported studies, involving 27 different vaccines. One of the newest trials opened earlier this year in Africa to help determine if vaccines have to be customized for different parts of the world.
Among the ongoing studies are trials of several innovative approaches to immunization. In one, the vaccine is applied to the tissues lining the vagina, rectum, and other mucosal surfaces where most HIV infections are acquired. Another uses a non-disease-causing type of the Salmonella bacteria to introduce an HIV protein to the immune system.
Most of the studies in progress are "phase one" trials -- meaning the objective is to evaluate the safety of the vaccine being tested. In June 1998, the first efficacy trial was launched. It is expected to last three years and involve 5,000 volunteers in the United States, Canada, and the Netherlands. In June of 1999, NIAID reported that preliminary analysis of data from a trial testing two vaccines given together showed that the combo is safe and capable of stimulating immune responses against HIV. In this study, the 435 volunteer participants aren't infected with HIV and are in no danger because the vaccines contain only selected HIV genes or proteins, not the whole virus.
Also, in June of 1999, participants in the 12th World Conference on AIDS discussed a $500 million plan aimed at finding an AIDS vaccine by accelerating the most promising studies. The plan, devised by the International AIDS Vaccine Initiative (IAVI), would speed vaccines toward human testing in third world countries, where 90 percent of new HIV infections occur.
You might be interested to know that you can keep up with news about AIDS and the vaccines under development online. NIAID provides twice daily updates of AIDS-related news from around the world at www.niaid.nih.gov/vaccines.