The Army-led Thai HIV vaccine efficacy trial, known as RV144, tested the “prime-boost” combination of two vaccines: ALVAC® HIV vaccine (the prime) and AIDSVAX® B/E vaccine (the boost). The vaccine combination was based on HIV strains that commonly circulate in Thailand.
RV144 and its follow-on trials allowed researchers to discover correlates of risk, provided targets for optimizing vaccine boosting, and provides a critical comparison for more recent HIV vaccine candidate trials.
Results
The trial demonstrated that the prime-boost vaccine regimen was safe and modestly effective in preventing HIV infection, lowering the rate of HIV infection by 31.2 percent compared to placebo based on the modified intent-to-treat (mITT) population (n=51 vs. n=74, respectively; p=0.04). It is the only HIV vaccine trial to date to demonstrate efficacy in preventing HIV infection. Study results, announced by the Army in 2009 and published in the New England Journal of Medicine, showed that a preventive HIV vaccine is possible, revitalizing the research field and providing hope for millions.
The landmark trial launched MHRP's global reputation in HIV research and opened the door to dozens of collaborations around the world. The Thai trial continues to provide scientific direction to help guide vaccine development and testing. MHRP researchers and worldwide partners have made substantive progress in understanding what it will take to develop a more efficacious HIV vaccine. RV144 and its follow-on trials allowed researchers to discover correlates of risk and provided targets for optimizing vaccine formulation and regimens.