Merck's decision last month to halt its international HIV vaccine trial was not a "definitive blow" to HIV vaccine research and development, but it created questions about whether research was "careening down the wrong path," the Philadelphia Inquirer reports (Stark, Philadelphia Inquirer, 10/7). Merck announced that it had ended its Phase II trial, which began in late 2004 and involved 3,000 HIV-negative volunteers, after its experimental vaccine failed to prevent HIV infection in participants or prove effective in delaying the progression of the virus to AIDS. The trial was stopped by the Data and Safety Monitoring Board, an independent overseer.
Some researchers have theorized that because HIV-positive people who have stronger T-cell responses tend to fight the virus better, a vaccine that simulated a T-cell response might be able to control HIV/AIDS. The Merck vaccine was made from a weakened version of a common cold virus that served as a mode for providing three synthetically produced genes from HIV, known as gag, pol and nef (Kaiser Daily HIV/AIDS Report, 9/24). According to Mark Feinberg, Merck's vice president for Medical Affairs for Vaccines and Infectious Diseases, an estimated 90% of vaccine studies were using major elements of Merck's experimental vaccine.
Some researchers said the trial might prove useful for researchers. "The information is going to help us develop a vaccine in the future," Ian Frank -- director of the HIV Vaccine Trials Unit at the University of Pennsylvania, which enrolled 125 people in Merck's trial -- said, adding, "I don't think people should be overly disappointed. We're really at the very earliest stages in this process." Gary Nabel, director of NIH's Vaccine Research Center, said, "To paraphrase some of my colleagues, the trial shows a failure of a specific product but not a failure of a concept," adding that it would be "truly remarkable" to see an effective vaccine developed in the next 10 years.
John Shiver, head of Merck's basic research in vaccines, said he believes that no current approaches toward HIV vaccine development are working and that a new approach is needed. The world is spending $759 million annually on HIV vaccine development, up from $150 million annually in the 1990s, Seth Berkley, president of the International AIDS Vaccine Initiative, said. More than 90% of the funding is coming from governments, the Inquirer reports (Philadelphia Inquirer, 10/7).
Related Editorial
The halt of Merck's HIV vaccine trial is "not the death of the quest; it's an opportunity to bend more strength to it," an Inquirer editorial says. Because of previous research that did not yield an effective HIV vaccine, we know much more about how the "fiendishly well-armed retrovirus associated with AIDS operates," according to the editorial. The Inquirer adds "our failures guide us to our successes" and "failures should spur funders not only to keep backing research and development, but also to step it up." This "quest will need friends in society and government," that is, "if we really care," the editorial concludes (Philadelphia Inquirer, 10/6).
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