Bangkok Post - July 31, 2007
Apiradee Treerutkuarkul

Chief researcher Supachai Rerksngarm said his team needed to extend the research until 2009 before concluding whether the vaccine was effective and could be produced on an industrial scale.

"It's still too early to say if the vaccine is effective in terms of preventing people from Aids infection as the results that have emerged so far are not as effective as we expected," he said after a trip to the United States where he participated in the interim analysis with a team of vaccine experts last week.

The project received funding from pharmaceutical firms and health advocacy groups in the US along with the Thai Public Health Ministry.

The researchers' goal was to make the vaccine 80% effective after two years of research which began in October 2003. But the latest results showed only about 50-60% effectiveness, he said.

But Dr Supachai insisted the clinical trials were still following the plan, which is scheduled to end in July 2009.

A stumbling block in the project primarily involved the shortage of volunteers as it took a long time before all 16,000 people in the provinces of Chon Buri and Rayong were recruited as planned.

Each volunteer was given either a vaccine or a placebo over a one-year period and followed up after at least three and a half years.

The so-called prime-boost test combines two vaccines-Alvac, which was created by France-based Aventis Pasteur, and AidVAX B/E, made by the California based VaxGen Inc, to stimulate different immune response systems simultaneously. The trial in Thailand was the first time the two vaccines were combined as experts believed the combination was an effective alternative to HIV/Aids control. Previously, research projects in Africa had used only one vaccine at a time and the results were not satisfactory.

However, some researchers have questioned the vaccine's validity, and the scientific ethics and efficacy of the trial.

A group of 22 prominent Aids researchers in 2004 wrote in the journal Science that the trials should be halted because of the high cost and because the two vaccines used in the Phase I and Phase II clinical trials were ineffective in preventing HIV transmission.

But Dr Supachai remained positive about the trials, saying the combination vaccine showed promising results. Efficacy of the earlier vaccine trial among sex workers in Bangkok was about 30% compared to the AidVAX trial at 50%.

In order to produce the vaccine on an industrial scale, the efficacy level should be no lower than 50%.

According to the deal with the pharmaceutical firms participating in the project, volunteers getting the placebo would receive the vaccine for free if the trial proved successful. In addition, the firms had to provide three million Aids vaccine doses for Chon Buri and Rayong residents within five years, he said.

070731
BP070707

Always watch for outdated information. This article first appeared in 2007. This material is designed to support, not replace, the relationship that exists between you and your doctor.

AEGiS presents published material, reprinted with permission and neither endorses nor opposes any material. All information contained on this website, including information relating to health conditions, products, and treatments, is for informational purposes only. It is often presented in summary or aggregate form. It is not meant to be a substitute for the advice provided by your own physician or other medical professionals. Always discuss treatment options with a doctor who specializes in treating HIV.

Copyright ©1980, 2007. AEGiS. All materials appearing on AEGiS are protected by copyright as a collective work or compilation under U.S. copyright and other laws and are the property of AEGiS, or the party credited as the provider of the content. .