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.) Read more
From left: RSPH dean Jim Curran, First Lady Jeannette Kagame, HIV/AIDS researcher Susan Allen, Vice Provost Philip Wainwright
Most of the discussion, when Rwanda’s First Lady Jeannette Kagame recently visited Emory, was not about HIV vaccines, and rightly so. It was about how far Rwanda has come as a country since the 1994 genocide [videos of author Philip Gourevitch discussing Rwanda].
Still,Â while introducing the First Lady and thanking her for her support of HIV/AIDS research in Rwanda, Susan Allen mentioned a clinical trial for a HIV vaccine that began last year in Rwanda, Kenya and the United Kingdom and is now wrapping up the vaccination phase. Her colleague in Kigali, Etienne Karita, is one of the principal investigators.
The vaccine uses replicating Sendai virus, which causes respiratory tract illness in rodents but not in humans, as a vector to deliver the HIV gag gene. The trial combines this vaccine, administered intranasally, in various configurationsÂ with an adenovirus-based vaccine. This is the first time that Sendai virus is beingÂ used in a HIV vaccine.
As IAVI Report’s Regina McEnery explains,Â researchers hope the Sendai vector might recruit targeted immune responses to mucosal tissues and provide an edge to the immune system when it is subsequently challenged by HIV.
In a future post, we plan to provide an additional update on HIV vaccine research, focusing on GeoVax and (separate, for comparison) a planned large-scale followup to the landmark RV144 Thai trial.
Two presentations on Emory research at last week’s AIDS Vaccine 2010 conference concerned adjuvants. These are substances that act as amplifiers, stimulating the immune system while keeping its focus on the specific components of a vaccine.
Charlie Janeway (1943-2003)
Immunologist Charlie Janeway once described adjuvants as immunology’s “dirty little secret,” because for a long time scientists did not know how they worked. Some adjuvants can sound irritating and nasty, such as alum and oil emulsion. Alum is the only vaccine adjuvant now licensed for human clinical use in the US. Over the last few years, scientists have learned that adjuvants rev up what is now known as the “innate immune system,” so that the body knows that the vaccine is something foreign and dangerous.
Rama Rao Amara, a vaccine researcher at Emory Vaccine Center and Yerkes National Primate Research Center, and Harriet Robinson, former head of microbiology and immunology at Yerkes and now chief scientific officer at the firm GeoVax, both described extra ingredients for the DNA/MVA vaccine that Robinson designed while at Yerkes in collaboration with NIH researchers.
Riders gather at the Hope Clinic of the Emory Vaccine Center for the final leg of their ride.
More than 130 bicyclists rode 200 miles in two days to raise $188,660 for AIDS vaccine research at the Emory Vaccine Center. The AIDS Vaccine 200 on May 22-23, sponsored by Action Cycling Atlanta, was the eighth annual ride. The series now has raised more than $680,000 for AIDS vaccine research.
This year’s riders traveled from Emory to Eatonton, Georgia, and back to Emory along with a volunteer crew.
Because of generous sponsorships, Action Cycling donates 100 percent of funds raised by participants to AIDS vaccine research. These unrestricted funds fill gaps that cannot be met by grant dollars alone.
Posted on June 11, 2010