Experimental Therapeutic HIV Vaccine Suppressed Virus By At Least 80% in Small Group of Patients, Study Says
An experimental therapeutic HIV vaccine suppressed the virus in a small group of HIV-positive Brazilians for up to a year, according to a study published Sunday in the online edition of the British journal Nature Medicine, the San Francisco Chronicle reports. Drs. Jean-Marie Andrieu and Wei Lu of the Institute of Research for Vaccines and Immunotherapies for Cancer and AIDS in Paris led the research. Researchers administered the vaccine -- which is designed to treat the virus rather than prevent infection -- to 18 HIV-positive Brazilians who had never taken any antiretroviral drugs (Russell, San Francisco Chronicle, 11/29). Every two weeks, the patients received injections that contained a mixture of their own dendritic cells -- a type of cell that is in the first line of defense in the immune system -- and whole HIV that had been chemically inactivated. Dendritic cells mark invaders with an antigen, or "tag," that helps to activate lymphocytes, another type of immune system cell, according to AFP/Independent Online. However, HIV is able to avoid being marked with antigens, and therefore evades detection by the immune system. The goal of the vaccine is to stimulate dendritic cells to recognize and mark the virus in order to mount a larger immune response (AFP/Independent Online, 11/29).
Four months after their first immunization, the patients' viral load levels were reduced by a median of 80%, Reuters reports. At the end of one year, eight of the patients had viral load levels that were 90% lower than their baseline levels (Reuters, 11/29). In addition, four patients' viral load levels were less than 1,000 copies per milliliter, a level so low that "in theory" means they "are not infective," Andrieu said, AFP/Independent Online reports. In addition, the patients' CD4+ T cell counts initially increased but fell back to their baseline levels. None of the patients experienced side effects (AFP/Independent Online, 11/29).
Costs, Next Steps
Currently, the vaccine is "impractical" to deliver to large numbers of people because it is "essentially custom made" for each patient, the Chronicle reports. Andrieu estimated that the cost of the treatment for one year could be $4,000 to $8,000 per person (San Francisco Chronicle, 11/29). Although the trial results suggest that this type of therapeutic vaccine shows potential to treat HIV-positive people, the researchers cautioned that additional research is necessary, Reuters reports. "We should emphasize ... that the efficacy of such a therapeutic vaccine will not be definitively proven until a randomized trial with an appropriate control arm has been performed," the researchers wrote (Reuters, 11/29).
Several CBS news programs reported on the French HIV vaccine research:
- CBS' "Evening News": The segment includes comments from Andrieu and Ana Oliveira of the Gay Men's Health Crisis Center (Pinkston, "Evening News," CBS, 11/28). The complete segment is available online in RealPlayer.
- CBS' "Evening News": The segment includes an interview with Anthony Fauci, director of the NIH National Institute of Allergy and Infectious Diseases (Brzezinski, "Evening News," CBS, 11/28). The complete segment is available online in RealPlayer.
- CBS' "Evening News": The segment includes comments from Andrieu and Jay Levy of the University of California-San Francisco's AIDS Research Institute (Kaledin, "Evening News," CBS, 11/29). The complete segment is available online in RealPlayer.