RV 144

RV 144, or the Thai trial, is the name of an HIV vaccine clinical trial combining two vaccines that failed on their own, vaccinating in Thailand over the course of 24 weeks in October 2003 then testing for HIV until July 2006 [2], publicly releasing efficacy findings in September 2009. The initial report shows that the rate of HIV infection among volunteers who received the experimental vaccine was 31% lower than the rate of HIV infection in volunteers who received the placebo.

The trial collaborators have stated that results of this trial give the first supporting evidence of any vaccine being effective in lowering the risk of contracting HIV. On October 20, 2009, the organizers released full results of the study through publishing in the New England Journal of Medicine and presented them at the AIDS Vaccine Conference in Paris.

A total of 16,402 Thai volunteers aged 18–30 were recruited to participate in Chon Buri and Rayong Provinces in Thailand. These volunteers were randomized into double-blind study groups, with those in the experimental group receiving a phase III prime-boost HIV vaccine. Eligibility criteria for participation in the study required that all volunteers be HIV negative prior to enrollment in the study and be willing to participate in educational counseling intended to teach ways to reduce risk behavior associated with contracting HIV. After being vaccinated, volunteers were asked to receive HIV testing every six months for three years, as well as receive additional risk-behavior counseling at every testing visit.

Of note, before this vaccine trial was initiated, an opinion letter from 22 established HIV researchers was published in the journal Science calling into question the rationale for this study of combining two vaccines that each failed in prior human trials to generate immune responses that they were designed to elicit. This letter stated that spending $119 million when "the overall approval process lacked input from independent immunologists and virologists who could have judged whether the trial was scientifically meritorious" was an ill-advised use of precious resources.

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