This colorized scanning electron micrograph shows human cells in a lab infected with "pink" influenza viruses. As many as 650,000 people each year die from flu, according to the World Health Organization. Steve Gschmeissner/Science Source hide caption
Lipitor, a best-seller as a cholesterol treatment, is being tested as a remedy for the flu. Mel Evans/AP hide caption
People 6 months and older should get vaccinated against the flu, says this government poster on display in a health center in Decatur, Ga. David Goldman/AP hide caption
Part of Nebraska's 2009 stockpile of the anti-viral medicine, Tamiflu. William Wiley/AP hide caption