Seattle Post-Intelligencer examines reactions of people who participated in Merck's canceled HIV vaccine

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Nov 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).

Comments
"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." Sarah Alexander, spokesperson for HVTN at the Fred Hutchison Cancer Research Center, said it has been difficult for the center to handle the cancellation of the trial and distribute announcements to volunteers. "People are asking us questions that we don't have answers to," Alexander said (Seattle Post-Intelligencer, 11/9).

Additional Coverage
Two other sources also examined Merck's experimental HIV vaccine.

Reuters: Researchers meeting last week in Seattle to discuss the trial data still do not know why the vaccine made people more susceptible to HIV, Reuters reports. According to Reuters, it is possible that using a common cold virus as the basis of the vaccine could have made participants more vulnerable to HIV. The men who became HIV-positive had the highest immune response to the cold virus. The HIV-positive men also were less likely to have been circumcised and could have engaged in more risky behavior, Reuters reports. Researchers agree that the outcome of the trial could "scare people" away from participating in other HIV vaccine research, according to Reuters. "That is why [officials] are being completely transparent, as open as possible," Anthony Fauci, director of NIH's National Institute of Allergy and Infectious Diseases, said recently, adding, "This setback should not and can not diminish our commitment to developing an effective HIV vaccine" (Fox, Reuters, 11/8).

Time Magazine: While Merck's HIV vaccine was not successful, it still "yields clues to how it might work next time," Time reports. One explanation for the failure might be that the researchers used a common cold virus and that most people have some immunity to such viruses. According to Time, a possible solution would be to continue using the cold virus but employ different HIV genes and administer two injections spaced a few months apart (Park, Time Magazine, 11/8).

Broadcast Coverage

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.

This article was reprinted from khn.org with permission from the Henry J. Kaiser Family Foundation. Kaiser Health News, an editorially independent news service, is a program of the Kaiser Family Foundation, a nonpartisan health care policy research organization unaffiliated with Kaiser Permanente.