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September 22, 2005

Flu Vaccines Don't Work; Tamiflu Effective

The New York Times reports:
Just as governments around the world are stockpiling millions of doses of flu vaccine and antiviral drugs in anticipation of a potential influenza pandemic, two new research papers published today have found that such treatments are far less effective than previously thought.

"The studies published today reinforce the shortcomings of our efforts to control influenza," wrote Dr. Guan Yi, a virologist at the University of Hong Kong, in an editorial that accompanied the papers. The two studies were published early online by the British medical journal, the Lancet, because of their implications for the upcoming flu season.

In one paper, international researchers analyzed all the data from patient studies on the flu vaccine performed worldwide in the past 37 years and discovered that vaccines showed at best a "modest" ability to prevent influenza or its complications in elderly people.

"The runaway 100 percent effectiveness that's touted by proponents was nowhere to be seen," said Tom Jefferson, a Rome-based researcher with the Cochrane Vaccine Fields project, an international consortium of scientists who perform systematic reviews of research data.

"There is a wild overestimation of the impact of these vaccines in the community," Dr. Jefferson said. "In the case of a pandemic, we are unsure from the data whether these vaccines would work on the elderly."

In the second paper, researchers from the Centers for Disease Control found that influenza viruses, particularly those from the dreaded bird flu strain, had developed high rates of resistance to older and cheaper antiviral drugs - rates that have escalated rapidly since 2003, particularly in Asia.

"We were alarmed to find such a dramatic increase in drug resistance in circulating human influenza viruses in recent years," said Dr. Rick Bright of the Centers for Disease Control, in Atlanta. "Our report has broad implications for agencies and governments planning to stockpile these drugs for epidemic and pandemic strains of influenza."

Before 2000, almost no virus was resistant to the drug Amantadine. By 2004, 15 percent of influenza A viruses collected in South Korea, 70 percent in Hong Kong and 74 percent in China were impervious. During the first six months of 2005, 15 percent of the influenza A viruses in the United States were resistant, up from 2 percent the year before. All human cases of the bird flu (H5N1) strain - which is still extremely rare in humans - have been resistant, the researchers said.

The immediate implications of these finding are most ominous for the developing world, because wealthier nations have been stockpiling newer and vastly more expensive antiviral medicines, like Tamiflu, which are effective against the disease but still on patent.

..."What you see is that marketing rules the response to influenza, and scientific evidence comes fourth or fifth," Dr. Jefferson said. "Vaccines may have a role, but they appear to have a modest effect. The best strategy to prevent the illness is to wash your hands."

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Posted by dymaxion at September 22, 2005 08:22 PM

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