November 14, 2007
Leaders of Merck's experimental HIV vaccine study on Monday decided to notify all of the trial's 3,000 participants whether they were given the vaccine or a placebo, the San Francisco Chronicle reports. Representatives of Merck, NIH and a group of physicians who enrolled the trial participants decided to unblind the study after several days of discussions at an HIV Vaccine Trials Network conference last week in Seattle (Russell, San Francisco Chronicle, 11/14).
Merck in September announced that it had ended the Phase II trial, which began in late 2004 and involved HIV-negative volunteers, after the 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. Data recently suggested that the vaccine was ineffective among some trial participants with a pre-existing immunity to a common cold virus and that the vaccine might have increased their susceptibility to HIV infection.
Researchers late last month asked trial participants to return to study sites for tests and additional follow-up regarding a possible increased risk of HIV. Researchers in South Africa who were testing the same vaccine have told the 801 participants in the separate trial if they received the vaccine (Kaiser Daily HIV/AIDS Report, 11/12).
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.