POZ Community Forums
Meds, Mind, Body & Benefits => Research News & Studies => Topic started by: Miss Philicia on July 17, 2008, 04:55:31 pm
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source (http://www.nytimes.com/2008/07/18/health/18vaccine.html)
July 18, 2008
Plans for Human Trial of H.I.V. Vaccine Canceled
By LAWRENCE K. ALTMAN
Plans for a large human trial of a vaccine against the AIDS virus in the United States were canceled on Thursday because federal health officials said the vaccine was unlikely to prove effective and might increase the risk of H.I.V. infection among volunteers.
The decision is another major setback in efforts to develop an H.I.V. vaccine, which health officials contend would be their best weapon to control the AIDS pandemic. Several other H.I.V. vaccines are in various stages of testing among people in many countries.
Scientists have been trying for more than 25 years to make an effective H.I.V. vaccine. They say that getting one to market — if one is ever developed — is years off.
After a meeting sponsored by the National Institute of Allergy and Infectious Diseases in March, many AIDS experts said researchers needed to go back to the drawing board before they could develop an effective vaccine.
The trial canceled on Thursday was supposed to have begun enrolling 8,500 volunteers last October to receive a vaccine developed by the infectious diseases agency. The study is known as PAVE, for Partnership for AIDS Vaccine Evaluation. PAVE is a consortium of United States government agencies and government-financed organizations involved in developing and evaluating experimental H.I.V. vaccines. Its goal is to develop an effective vaccine that no pharmaceutical company or institution is likely to accomplish on its own.
But the PAVE trial was postponed after a test of a similar, much-heralded vaccine made by Merck failed in its two main objectives: to prevent infection and to lower the amount of H.I.V. in the blood among those who did become infected.
Also, the findings among the 3,000 participants in nine countries in which the Merck vaccine was tested suggested it might have increased the risk of becoming infected with H.I.V.
After a safety monitoring committee detected the problems with the Merck vaccine in September, the company stopped its study immediately.
Scientists have found no obvious explanation for the failure of the Merck vaccine, which had been considered the most promising candidate for an H.I.V. vaccine. The infectious diseases agency helped pay for the vaccine trials.
The Merck vaccine was the first of a new class of H.I.V. vaccines to get to an advanced stage in human testing. The vaccine was made from a weakened version of a common cold virus, adenovirus type 5, which served as a way to deliver three synthetically produced genes from the AIDS virus. Three doses of the vaccine were injected over six months.
Scientific analyses found that the highest risk of H.I.V. infection among recipients of the Merck vaccine were among males who were both uncircumcised and had pre-existing antibodies to adenovirus type 5.
After the failure of Merck trial, the government reduced the number of potential volunteers to 2,400. They would include gay men who were circumcised and who had no pre-existing antibodies to adenovirus type 5. The study would have cost about $63 million.
Dr. Anthony S. Fauci, the director of infectious diseases agency, now says he would consider a proposal from scientists to conduct a small human trial to focus on only one goal: to determine if the PAVE vaccine significantly lowers the amount of H.I.V. in the blood of vaccinated participants who may later become infected with H.I.V.
At a news conference in 1984, top United States government officials said they were optimistic that a marketable H.I.V. vaccine would be available in three years.
Since then, AIDS researchers have been divided about how fast to test experimental vaccines.
Many urge caution out of fear that failures could destroy confidence among uninfected people most at risk who would be needed as volunteers in future trials.
But equally vocal groups call for testing everything as soon as the research shows promise because of the urgent need for a vaccine.
In an unrelated development, researchers at Duke reported new findings showing that H.I.V. stuns the immune system earlier than scientists prevously understood. The window of opportunity in stopping H.I.V. may be a matter concerning the first few days — not weeks — after the virus enters the body, a team headed by Dr. Barton Haynes reported in The Journal of Virology. The findings were based on a study of 30 individuals newly infected with H.I.V. The study was paid for by the National Institutes of Health.
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:'(
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attract more young investigators to HIV vaccine research
$15.6 million project to study antibody responses from B cells instead of targeting T cells
program to fund research into how HIV transmission can be interrupted.
move to basic research
http://www.the-scientist.com/blog/display/54888/ TODAY
"The general trend will be funding a bit more fundamental discovery research," Fauci said, echoing a pledge he made at an NIAID conference back in March.
NIAID is still solidifying some future initiatives, Fauci said, such as plans to attract more young investigators to HIV vaccine research by offering more grants for such studies, and to encourage more collaboration between non-human primate researchers and scientists at human clinical centers. The NIAID is also planning a November conference on non-human primate research on HIV vaccines, Fauci said, and in May funded a $15.6 million project to study antibody responses from B cells instead of targeting T cells - the approach taken by previous vaccine efforts. More recently, NIAID announced another program to fund research into how HIV transmission can be interrupted. The move to basic research "doesn't mean we're going to stop all clinical trials," Fauci explained. Instead, he said, the scientific bar for taking an HIV vaccine candidate into the realm of clinical trials has been raised.