The so-called Spanish flu struck in the final months of world war one, rapidly killing more people than died in that entire bloody war. As many as one-hundred million people perished worldwide. The suffering was horrific.
"Their skin could turn so dark blue from lack of oxygen that one physician reported that he had difficulty telling African American troops from white troops. People could bleed from not only from their mouth and nose but even from their eyes and ears."
"The only thing I can think off that could take a larger human death toll than virulent pandemic influenza would be thermonuclear war"
And Laurie Garret who studies the flu is worried it could all happen again.
"The problem with flu is its orders of magnitude, more contagious then the dreaded ebola virus; than smallpox which we have been preparing as a nation for as a possible bio terrorist weapon, than just about anything except the common cold."
A single sneeze ejects millions of flu viruses into the air. And the virus can live as long as two days, even on a cold surface, like a doorknob.
Today's medicine may be more advanced than in 1918. Antibiotics can stop pneumonia complications. But anti-flu drugs such as Tamiflu or Relenza offer just partial protection. There's an experimental vaccine against bird flu, but no one really knows if it will work.
And remember, back in 1918, the virus couldn't hitch a ride on a plane.
"It circumnavigated earth three times in 18 months when there was no commercial air travel. There were a lot fewer human beings; we did not have globalized economy, Americans rarely left America, and Europeans rarely left outside of Europe.
Hardly anybody went to China, except Chinese in 1918; now look at us."
Today's deadly bird flu is literally less than 24 hours away.