September 24, 2009
BANGKOK (AFP) - If an experimental AIDS vaccine proves to be the watershed that scientists have claimed, then it is volunteers like Thai farmer Aree Kamphonrat who risked their health to make it a success.
"I wanted to help all countries to fight HIV and also I wanted children not to get infected by HIV," said Aree, one of 16,402 volunteers who took part in the world's largest AIDS vaccine trial.
The study, which ran from 2003 to 2006 took place in the Thai provinces of Chonburi and Rayong, both near Bangkok, and tested willing HIV negative men and women aged from 18 to 30 at average risk of infection.
Half of the volunteers received the vaccine and the rest were given a placebo. Aree said she had six jabs, but like all the volunteers she was not told whether she was given the vaccine or the dummy injection.
"A lot of people in my village got involved with the programme," said Aree, who is from Rayong and is now aged 32, explaining that she had to have a blood test and fill in a written application to take part.
The experimental vaccine tested in the trial was a combination of two older shots that had not reduced infection on their own, based on strains of HIV that commonly circulate in Thailand.
These were the canarypox vaccine ALVAC, manufactured by Sanofi-Aventis of France, and AIDSVAX, originally made by VaxGen Inc and now licensed to the non-profit, San Francisco-based Global Solutions for Infectious Diseases.
Researchers said that before agreeing to participate, all volunteers were informed of and consented to the potential risks of the treatment.
But the study vaccines "did not cause infection because they are not made from and do not contain the entire virus, either live or killed," a statement from the research team said.
As the study began, the volunteers received counselling on how to prevent becoming infected with HIV, with further sessions every six months after the start of the trial, for more than three years.
Researchers said those who did acquire HIV during the study were given free access to HIV care and treatment.
Out of the placebo recipients 74 of 8,198 became infected, compared with 51 of 8,197 who got the vaccine -- meaning the vaccine lowered the rate of HIV infection by 31.2 percent compared with the placebo.
However the trial found that the vaccine was unable to reduce the amount of HIV in the blood -- known as the "viral load" -- of those who became infected.
But the participants were still pleased with the outcome.
"The results were good and it's a good opportunity for Thailand to develop the vaccine," Aree added.
