If all the good advice about coughing and sneezing into your sleeve to prevent the spread of flu hasn't sunk in, please take a look at this gripping video from NPR's Robert Krulwich and medical animator David Bolinsky.
Now, you can see how the flu virus—any flu virus—propelled by one man's sneeze—any man's sneeze—infects another poor guy, hijacking a cell to make a whole bunch more virus which could infect you.
The new H1N1 virus is doing a lot of this lately. The Centers of Disease Control and Prevention said Friday that since April, when swine flu first hit, the multiplying bug has caused more than 1,000 deaths and put more than 20,000 people in the hospital. Here's how that gets rolling.
Bonus protection: Flu spreads through handshakes, too, so we offer some alternative greetings that might help curb the pandemic. Personally, we hope the Snap and Flick catches on.