Ten years ago, the results of the RV144 trial– conducted in Thailand with the help of the US Army — re-energized the HIV vaccine field, which had been down in the dumps. It was the first vaccine clinical trial to ever demonstrate any efficacy in preventing HIV. The Hope Clinic of Emory Vaccine Center has been involved in efforts to build on the RV144 trial’s promising results. These early-stage studies have been optimizing the best vaccine components and techniques for larger vaccine efficacy trials, some of which are now underway.
Nadine Rouphael, interim director of the Hope Clinic, was first author on a recent paper in Journal of Clinical Investigation, reporting a multi-center study from the HIV Vaccine Trials Network. HVTN is headquartered at the Fred Hutchinson Cancer Research Center in Seattle and supported by the National Institute of Allergy and Infectious Diseases.
“Our study shows that there are tools available to us now to improve on the immunogenicity seen in RV144, which may lead to better efficacy in future field trials,” Rouphael says. (See statement on the HVTN 105 study here.)
The HVTN 105 study looked whether DNA and protein combination vaccine regimens were effective at inducing antibody and T cell responses, but did not test whether they were capable of preventing infection. HVTN 105 substituted the workhorse canarypox viral vector used in RV144 (ALVAC) with DNA. According to the JCI paper, no DNA vaccine is currently licensed for use in humans, but many are in the research pipeline.
The authors conclude: “Based on our study, DNA provides a suitable alternative platform to ALVAC; however, a larger efficacy study is needed to confirm the findings of our proof of concept…DNA appears to be a good alternative to viral vectors, and its early coadministration with protein can rapidly induce a potentially protective antibody response that would enhance its value to public health.”
The similar HVTN 96 study, conducted in Lausanne, was also recently published in The Lancet HIV.