"This trial will be recognized as a testament to Thailand's ability to successfully execute a complicated vaccine trial, the largest ever attempted, that ended with a credible conclusion, and that brought us one step closer to an HIV vaccine," said U.S. Ambassador to Thailand Eric John.
The clinical trial was sponsored in part by the U.S. Army and conducted by the Thailand Ministry of Public Health. A combination of two, previously unsuccessful vaccines cut the risk of becoming infected with HIV by more than 31 percent.
The study used strains of HIV common in Thailand. It's not yet known if the vaccine would work against other strains in the U.S., Africa or elsewhere in the world.