Peliminery findings of phase I AIDS vaccine trial,under way at Punes National AIDS Research Institute and Chennais Tuberculosis Research Centre (TRC),said the vaccine was safe. Dr A Risbud,acting director of NARI told The Indian Express that the results of the phase 1 vaccine trial were presented by researchers at the ongoing AIDS vaccine 2010 conference in Atlanta,USA. The study is an ongoing one and results are based on preliminary,blinded data. We have found the vaccines ability to elicit a modest immune response, said Risbud. The vaccine trial used ADVAX,a DNA-based vaccine,as the prime and Modified Vaccinia Ankara (MVA) as the boost. ADVAX was earlier tested in the US and found to be safe. Similarly,MVA vector,which was earlier tested at the Chennai-based TRC in 2008,showed that the vaccine was safe. According to Risbud,there were no serious adverse events that were reported during the trial. The trial will be completed after one more follow up visit of volunteers later this year. The final results will be available next year, said Risbud. The prime-boost vaccine has shown only a modest immune response. According to Risbud,priming is to give one type of vaccine dose to induce certain kind of immune response,to be followed by or together with a second type of vaccine (booster). A prime-boost combination may induce different types of immune responses and/or enhance overall responses beyond those seen with only one type of vaccine. The magnitude of the immune response was only modest. A vaccine can be called efficacious when the immune responses are seen in a large number of volunteers and are persistent, said researchers.
