“Given the significant threat of HIV infection worldwide, an effective vaccine is urgently needed as part of a broader prevention effort to help control the epidemic.” – U.S. Military HIV Research Program
Until recently, hopes of an effective vaccine against HIV remained dim even though a vaccine could potentially impact millions of lives worldwide.
Everyone, from the Global HIV Vaccine Enterprise to the National Institute of Allergy and Infectious Diseases to the man on the street, has dreamed of and/or worked toward the creation of a vaccine that prevents HIV infections. Even with this huge, global effort, HIV vaccine research languished until a Thai HIV vaccine clinical trial found a modicum of success in 2009.
This U.S. Army and Thailand Ministry of Public Health-sponsored trial, known as RV144, was conducted in Thailand with 16,000 volunteers. The vaccine successfully reduced the HIV infection rate by 31.2%, a relatively modest but still significant scientific achievement. These results were heralded as a renaissance in HIV vaccine development.
The RV144 trial tested the ‘prime boost’ combination of two vaccines derived from two strains of HIV common in Thailand. While the vaccine had no impact on people once they were infected with HIV, it did decrease the number of new infections among recipients compared to those given a placebo.
Scientists don’t yet know why this regimen worked, but it is promising for several reasons:
- Both of the vaccine components used in the trial had previously failed when used individually. It was only when used in combination that positive outcomes resulted.
- Even with the modest success, a recent study showed that a semi-effective HIV vaccine given to part of the population could reduce new HIV infections by 1/3rd within 15 years.
- The study provides scientists with valuable information about how to conduct a large-scale HIV prevention trial.
The future of HIV vaccine research is looking much brighter than it did before results from RV144 were first reported in September 2009, yet further progress is not a foregone conclusion. The global financial crisis has reduced investment in HIV vaccine research and development by 10 percent. And capitalizing on the results of RV144 willrequire a sustained scientific commitment that some countries may no longer be able to afford.