ugnet_: FIRST AIDS VACCINE TRIAL A NO GO

[Mulindwa Edward]

Heavy Blow To World's First Mass AIDS Vaccine Trial 2-24-3 The outcome of the world's first AIDS vaccine to undergo mass trials on humans dealt a heavy blow to campaigners hoping for a shield against the global pandemic. Tested over three years, AIDSVAX failed to protect most volunteers against HIV infection but did apparently have some protective effect on blacks and Asians, its makers, VaxGen Inc., announced on Monday. The trial "did not show a statistically significant reduction of HIV infection within the study population as a whole, which was the primary endpoint of the trial," it admitted. The vaccine or a dummy lookalike were administered in three doses to 5,009 volunteers, primarily gay men in the United States, as well as volunteers in Canada, Puerto Rico and the Netherlands. Two-thirds were given the vaccine, and one-third the placebo. The northern California biotech company said there was a "statistically significant" reduction of HIV infection amongst blacks and Asians. "There were 67 percent fewer HIV infections among ethnic minorities, other than Hispanic individuals," the company said Monday. "There were 78 percent fewer HIV infections among black volunteers who received vaccine compared to placebo recipients." Phillip Berman, VaxGen's senior vice president of Research and Development and inventor of the vaccine, said that those results were heartening. They showed "certain groups have a better immune response" to HIV and this warranted further study, he argued. However, that contention was questioned by the International AIDS Vaccine Initiative (IAVI), a New York-based organisation that is pushing hard to promote a vaccine against the human immunodeficiency virus (HIV). It said the number of infections among ethnic volunteers was too small to draw any firm conclusion. There were only 13 infections among black volunteers, four in the vaccine group and nine in the placebo group. In addition all the volunteers received counselling on safe sex, a factor known by scientists to affect infection rates. "The news on VaxGen's AIDSVAX is disappointing, but we are not discouraged," IAVI president Seth Berkley said. "The search for an AIDS vaccine will -- and must -- go on. "A vaccine is the world's best hope to end the spread of a virus that infects nearly 15,000 men, women and children daily and threatens the survival of whole communities." Peter Piot, executive director of the UN agency UNAIDS, said some of the results were "promising". "The trial provides clear evidence that a vaccine can work. However, there is an urgent need for more targeted research to find out why the candidate vaccine only seems to work in certain population sub-groups." AIDSVAX is the only vaccine to have been tested through all three phases of medical trials -- a long, arduous and expensive process for assessing safety and effectiveness that takes a candidate medicine out of the laboratory and into the public domain. The trial vaccine is based on priming antibodies, the first line of the body's defence. Its goal is to get the antibodies to identity the so-called gp120 protein on the surface of HIV which enables the virus to dock with an immune-system cell, the first stage before penetrating it. Although lab tests had shown that gp120 antibodies could be stimulated, there had already been some evidence to cast doubt on whether the response has the punch to destroy the virus. Disappointment with antibodies has prompted many AIDS vaccine researchers to try another tack, switching away from antibodies and towards cellular immunity: getting killer lymphocytes to recognise and destroy cells already infected by HIV. This would not, however, destroy virus in the bloodstream, which means it could still infect other people through, for instance, shared drug syringes. A senior European researcher said the results from this first-generation vaccine were a "disappointment" but "not a surprise." "We have known since the beginning that antibody-based vaccine strategies will not be enough to fight the incredible diversity of this virus," said Jean-Gerard Guillet, head of the preventive vaccine programme at ANRS, France's National AIDS Research Agency. Guillet added, however, that knowledge could only progress through the concrete results of mass trials. He put the typical cost of a Phase III trial at more than 70 million dollars. A Phase III trial of AIDSVAX is also underway among injection drug users in Thailand, testing a formulation that is designed to protect against the HIV subtypes B, which is prevalent in North America and Europe, and E, which is prevalent in central Africa and Southeast and East Asia. According to UN figures, around 20 million people have already died from acquired immune deficiency syndrome (AIDS) and another 42 million people had HIV or AIDS in 2002.              The Mulindwas Communication Group "With Yoweri Museveni Uganda is in Anarchy"              Le groupe de transmission de Mulindwas " avec Yoweri Museveni, Ouganda est dans anarchy "