After decades of waiting AIDS vaccine seems within reach
Although to date the history of HIV vaccine design has been largely unsuccessful the RV144 trial of 2009, a clinical trial involving more then 16 000 adults in Thailand, has scientists believing once again that an HIV vaccine is possible
Although to date the history of HIV vaccine design has been largely unsuccessful the RV144 trial of 2009, a clinical trial involving more then 16 000 adults in Thailand, has scientists believing once again that an HIV vaccine is possible. The Thai study tested Sanofi's ALVAC, a weakened canary pox virus used to covertly introduce three HIV genes into the body, and AIDSVAX, a vaccine originally made by Roche Holding's Genentech that carried an HIV surface protein. Both vaccines had poor showings in individual trials. However much to everyone’s surprise the vaccine combination cut HIV infections by 31.2 percent. Although the result was not big enough to be considered effective, it had a very positive impact on the research community. Three years on an extensive analysis of the Thai trial published this year in the New England Journal of Medicine offered clues about why some volunteers responded. The study, led by Dr. Barton Haynes of Duke University, scientists at Walter Reed and 25 other institutions, found men and women who were vaccinated made antibodies to a specific region of the virus's outer coat, suggesting this region provides an important vaccine target. Preparations are now under way for a follow-up trial testing versions of the vaccines among heterosexuals in South Africa and men who have sex with men in Thailand. Once again, the trial will use a Sanofi vaccine, but instead of AIDSVAX, researchers will use a vaccine candidate with a boosting agent from Novartis. Large-scale effectiveness studies are expected to start in 2016. With the hope to have at least 50 percent effectiveness, a level that mathematical modelers say could have a major impact on the epidemic.
