I believe the war was "called" on account of the flu. Everyone was running out of fighting age men.
Some notes from two different sources:
"The influenza of 1918-1919 was a influenza virus had a profound virulence, with a mortality rate at 2.5% ..."
From another source:
"Avian influenza is an infection caused by avian (bird) influenza (flu) viruses. ... and has a mortality rate that can reach 90-100% often within 48 hours. ..."
I've also read where the experts expect (hope?) the avian flu moratlity rate will decrease IF it ever goes human to human.
Here's what I've read the mortality is for the H5N1:
* 2005 = 55%
* 2006 = 70+%