A rapidly evolving strain of bird flu has killed a record number of people this year in China. Scientists are concerned about its potential to spur a global pandemic.
The Centers for Disease Control and Prevention wants more flexibility in deciding whom to quarantine and why. But critics say the changes the agency has proposed raise civil liberties questions.
More than $7 billion in drugs, vaccines and supplies are stashed in warehouses to be tapped in case of a pandemic or an attack with chemical, biological or nuclear weapons. NPR got a peek at one.
When it comes to talking about infectious diseases, researchers have their own special jargon. But even they aren't always 100 percent sure of the definitions.