Flu fallacies

10/7/2005

IF THE conclusions of two major medical studies on the flu and its remedies are valid, medical professionals and global leaders, especially those in the developing world, will have to dramatically rethink how to prevent and treat a potential influenza pandemic. The news is particularly troubling so close to the start of another flu season.

One study, done by an international group of scientists and published early online by the London-based medical journal Lancet, analyzed the effectiveness of the flu vaccine distributed worldwide for the last 37 years. Researchers found it to be "modest" at best in preventing influenza or its complications in elderly patients.

That's hugely significant because the flu vaccine has been strongly advocated for older people as sort of an insurance policy against the disease. Getting vaccinated against the flu has been standard practice for those considered more susceptible to flu-related complications and death.

"The runaway 100 percent effectiveness that's touted by proponents was nowhere to be seen," said Tom Jefferson, a participating researcher in Rome. "There is a wild overestimation of the impact of these vaccines in the community."

Based on all the data, the scientists say it's unclear whether the vaccines would make any difference on the elderly in a pandemic. Their case studies on patients over 65 showed the vaccines were "apparently ineffective" in preventing the spread of influenza, or pneumonia, or hospital admissions. To a moderate degree, the vaccines did appear to reduce death from pneumonia, and nursing home patients seemed to fare better if inoculated.

But for the most part, observed Mr. Jefferson, "What you see is that marketing rules the response to influenza, and scientific evidence comes fourth or fifth."

A second study done by researchers from the Centers for Disease Control and Prevention was even more alarming in its findings about drug-resistant human influenza viruses. The implications could be enormous for countries busy stockpiling vaccines in anticipation of epidemic or pandemic strains of influenza.

Before 2000 no virus was impervious to the antiviral drug Amantadine. Today, resistance is up dramatically. Last year resistance rates ranged from 15 percent of influenza A viruses collected in South Korea to 70 percent in Hong Kong and 74 percent in China.

In the United States, 15 percent of influenza A viruses studied the first six months of this year were resistant to the drug, up 2 percent from a year ago.

In response, wealthy countries have been rapidly stockpiling much more expensive antiviral drugs like Tamiflu, which are effective against the disease but still on patent. Poorer nations are at an obvious disadvantage to react likewise.

But all conventional medical responses to influenza may need to be evaluated. Researchers were startled to discover how quickly and unexpectedly viruses can become impervious to antiviral medicines once they are put into common use, as they would be in a pandemic.

The studies demand urgent attention with the advent of new and even more deadly diseases on the planet like the bird flu and sudden acute respiratory syndrome, or SARS.

The medical approach to these escalating health risks might be all wrong, and time is running out to find one that adapts to the danger.