The world is ever smaller. Flu strains incubating in China can be in New York or LA or DC in the span of a day. This is a world in which an incurable bacterial disease, spread by a tiny insect native to Asia, decimates the citrus crop in Florida.

On the surface, the flu vaccine seems like a no-brainer. History has shown us influenza can be a devastating and lethal disease worth attempting to control if not eradicate. However, looking more closely, we find that these apparent no-brainers do, in fact, present complicated policy questions.

Writers and filmmakers have long liked apocalyptic stories. But out in the real world, it might well be that the most likely cause of our specie's demise will be a microscopic bug we cannot defeat, and that we vanish, or vastly diminish, not with a bang but a whimper.

There are many people who are used to going to work when they are a bit under the weather. However, swine flu is changing that equation.