HOPES RISE FOR HIV VACCINE

       The world's largest HIV/Aids vaccine trial-conducted in Thailand over the last several years-shows it is now possible to produce a powerful prevention against the viral killer.
       "The outcome represents a breakthrough in HIV-vaccine development, because for the first time ever there is evidence an HIV vaccine can be effective," Public Health Minister Witthaya Kaewparadai said yesterday.
       However, while the Phase III trial, carried out jointly by the US military and Thai scientists, found the experimental vaccine was 31.2-per-cent effective in reducing the risk of infection, it failed to reduce the HIV virus in the blood of infected persons.
       Dr Supachai Rerk-ngarm, project director for Thailand's Phase III HIV vaccine clinical trial, said researchers had targeted a 50-per-cent efficacy rate but that the outcome was less: 31.2 per cent.
       "Although it's not high enough for use just yet, this is significant evidentce that can lead to higher vaccine efficacy in the future. Whether the vaccine will be licensed or what furthe studies need to be done, data will be considered thoroughly by Thai and international experts," he said.
       Colonel Jerome Kim of the US military's HIV research programme said via a video link that there could be an effective vaccine in the near future.
       "This is a turning point for the perspective of vaccine research," he said. "I believe that from now, scientists around the world will convene and discuss among each other on how to develop the next generation of HIV vaccine in the future."
       The Thai experiment, known as RV 144, tested the "prime boost" combination of two vaccines: Alvac HIV vaccine (the prime), produced by Sanofi-Pasteru; and Aidsvax B/E vaccine(the boost), produced by Global Solotions for Infectious Diseases.
       This combination was based on an HIV strain that commonly circulated in Thailand.

       VOLUNTEERS
       The RV 144 was designed to test the vaccine strategy's ability to prevent HIV infection and reduce the amount of HIV in the blood (viral load) of those who became infected after they enrolled in the study.
       The Public Health Ministry conducted the study, which was sponsored by the US Army Surgeon-General with US$105 million(Bt3.52 billion), while Mahidol University and the Armed Forced Research Institute of Medical Science, operating out of Thailand, helped conduct the trial.
       The Phase III vaccine study was launched in 2003 and involved 16,402 non-infected volunteers aged 18-30 at average risk of HIV infection.
       Half of them received the prime-boost vaccine combination and half received a placebo.
       The vaccinations ended in July 2006, and the volunteers took an HIV test every six months for three years.
       They received counselling on how to prevent infection with HIV at the beginning of the study and every six months after the start of the trial, for a total of three-and-a-half years.
       The International Data and Safety Monitoring Board did not identify any safety concerns after they met eight times since the trial's inception.
       The study vaccines did not cause HIV infection, because they are not made from and do not contain the ednire virus, live of killed.