Vaccine cuts AIDS infection risk for first time: researchers


-File photo

An experimental AIDS vaccine has for the first time cut the risk of infection, researchers said Thursday, hailing it as a medical ‘breakthrough’ in the quarter-century battle against the disease.
The vaccine reduced the risk of being infected by almost a third, they said after the world’s largest vaccine trial of more than 16,000 volunteers carried out by the US Army and the Thailand Ministry of Public Health.
“It is the first demonstration that a vaccine against HIV can protect against infection,” Colonel Jerome Kim of the US military HIV research programme told a news conference in Bangkok via videolink.
“This is a very important scientific advance and gives us hope that a globally effective vaccine may be possible in the future,” he said.
The vaccine was effectively a combination of two older vaccines that had not reduced infection on their own. It was tested on volunteers at average risk of HIV infection in two Thai provinces near Bangkok starting in October 2003.
The two older vaccines combined for the trial were ALVAC manufactured by Sanofi-Aventis and AIDSVAX made by VaxGen Inc.
“The outcome represents a breakthrough in HIV vaccine development because for the first time ever there is evidence that HIV vaccine has preventative efficacy,” said a statement released by the researchers.
“The vaccine has a 31.2 percent efficacy in reducing the risk of HIV infection.”
Thai Public Health Minister Witthaya Kaewparadai said the “outcome of this study is a scientific breakthrough.”
AIDS first came to public notice in 1981 and has since killed at least 25 million people, and 33 million others are living with AIDS or the HIV virus.
Swift progress in identifying the virus that caused it unleashed early optimism that a vaccine would quickly emerge. HIV destroys immune cells and exposes the body to opportunistic disease.
Out of the 50 candidates that have been evaluated among humans, only two vaccines have made it through all three phases of trials, and both were flops. About 30 vaccines remain in the pipeline.
US ambassador to Thailand Eric John said the vaccine trial had “incredible conclusions and brought us one step closer to an HIV vaccine”.
He said more research was needed but the results had “important implications” for a future vaccine.
Earlier this month in a study published in the journal Science, US researchers said they had discovered two powerful new antibodies which could hold the key to achieving a viable AIDS vaccine.
The antibodies are produced naturally by a minority of people infected with HIV and are able to neutralise a high percentage of the many types of the virus in circulation worldwide.

Copyright AFP (Agence France-Presse), 2009