The drug does none of the above. An FDA committee declined to approve Tamiflu in 1999 after finding that Tamiflu had not been shown to reduce pneumonia or mortality. But FDA administrators overruled the expert advisors and approved the drug. The agency later instructed the company to issue the following statement:

Tamiflu has not been proven to have a positive impact on the potential consequences (such as hospitalizations, mortality, or economic impact) of seasonal, avian, or pandemic influenza.

In 2009, a decade after the drug was approved, an FDA spokesperson told the BMJ (formerly the British Medical Journal) that clinical trials "failed to demonstrate any significant difference in rates of hospitalization, complications, or mortality in patients receiving either Tamiflu or placebo."

Last year, the prestigious Cochrane Collaboration, a group of experts in medical evidence, set about re-analyzing all the data they could lay their hands on about Tamiflu. When they examined seven studies of hospitalizations of flu patients given Tamiflu or placebo, Roche's drug showed "no effect." In other words, go to your doctor, pay your money -- and you're just as likely to end up sick enough to require hospitalization, whether or not you take the drug. The Cochrane study did find that flu symptoms were shortened by 21 hours, which hardly seems worth the risk of Tamiflu's side effects, which include vomiting and diarrhea. The drug has also been linked -- anecdotally -- to psychiatric symptoms.

Why does the CDC recommend Tamiflu as a first line treatment against the flu? (The agency also spends millions of dollars each year stockpiling and promoting flu vaccine, which is also of dubious value, as we wrote in an article for The Atlantic in 2009.)

When we asked the CDC to show us the data behind the decision, the agency responded, "CDC looks at more than clinical trial or randomized control trial data ... many observational studies ... have consistently found that early oseltamivir treatment of influenza patients reduces the duration of hospitalization and risk of severe outcomes such as intensive care unit admission or death." In other words, they're willing to throw out the scientific evidence in favor of observational studies.

But the most worrisome thing about the ongoing hype around Tamiflu is the emergency room crowding it is causing. Dr. David Newman, an associate professor of emergency medicine at Mount Sinai School of Medicine, in Manhattan, says that one of the biggest dangers of any flu season is the outbreak of panicky patients who flood emergency departments around the country. The vast majority don't even have the flu, they've got some other yucky virus. But of those with the flu, most aren't sick enough to need hospitalization. Even so, says Newman, when patients with even mild flu symptoms show up in the hospital, they spread whatever virus it is they have by sneezing and coughing in rooms that are jammed with other people.