November 12, 2007
The Seattle Post-Intelligencer on Friday examined the reaction of volunteers in the Seattle arm of Merck's recently halted HIV vaccine trial. According to the Post-Intelligencer, participants who were interviewed on the condition of anonymity have voiced "decidedly mixed feelings" about participating in the trial because of safety concerns (Paulson, Seattle Post-Intelligencer, 11/9).
New evidence suggests that Merck's experimental HIV vaccine was ineffective among some trial participants with a pre-existing immunity to a common cold virus and might have increased their susceptibility to HIV infection, researchers reported Wednesday at an HIV Vaccine Trials Network conference in Seattle. However, the researchers also said that the findings could be a statistical coincidence and that there is insufficient data to determine the full meaning of the findings. Merck in September 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.
Researchers late last month asked more than 3,000 people who participated in the trial to return to study sites for tests and additional follow-up regarding a possible increased risk of HIV. Conference attendees are debating whether the trial investigators should continue to observe the participants without telling them whether they received the vaccine or a placebo. Researchers in South Africa who were testing the same vaccine have told the 801 participants in the separate trial if they received the vaccine. A recommendation on whether to tell the 3,000 people enrolled in the study in the U.S. and Latin America will be made in about 10 days, Keith Gottesdiener, a Merck vice president, said (Kaiser Daily HIV/AIDS Report, 11/8).
"If I had known this vaccine could diminish my overall immunity (to HIV), I definitely would not have signed up," one 40-year-old man who participated in one of three studies said. However, another 37-year-old volunteer said that he "wanted to help find a way to combat" HIV and is "still committed to this study." A 40-year-old Seattle man and study volunteer added, "We desperately need an AIDS vaccine. If the study does get unblinded and it turns out I received a placebo, I'm going to sign up again."
Two other sources also examined Merck's experimental HIV vaccine.
NPR's "All Things Considered" on Friday reported on the vaccine. The segment includes comments from Glenda Gray of the University of the Witwatersrand's Perinatal HIV Research Unit, chief investigator for the trial in South Africa, and Margaret Johnston, director of the vaccine studies at NIH (Wilson, "All Things Considered," NPR, 11/9). Audio of the segment is available online.
Reprinted with permission from kaisernetwork.org. You can view the entire Kaiser Daily HIV/AIDS Report, search the archives, or sign up for email delivery at www.kaisernetwork.org/dailyreports/hiv. The Kaiser Daily HIV/AIDS Report is published for kaisernetwork.org, a free service of the Kaiser Family Foundation, by The Advisory Board Company. © 2007 by The Advisory Board Company and Kaiser Family Foundation. All rights reserved.