WASHINGTON -- It was the flu season to end all flu seasons.
In the waning days of World War I, a new strain of influenza appeared. Normally a mortal threat only to infants and the aged, this microbe was 25 times deadlier. It was often a swift and ferocious killer of otherwise healthy adults.
Between 20 million and 40 million died around the globe of the Spanish flu of 1918, probably the worst pandemic in human history. Almost a third of Americans were infected, and 675,000 died -- so many that, in a matter of months, U.S. life expectancy fell by 13 years.
Until recently, it was widely assumed that the secret of the Spanish flu's lethal nature died with its legions of victims. But earlier this year, Dr. Jeffrey K. Taubenberger and Ann H. Reid of the Armed Forces Institute of Pathology at the Walter Reed Army Medical Center announced they had discovered the shattered remains of the Spanish flu virus.
It was isolated from a sample of lung tissue, taken from an unfortunate soldier stationed at Fort Jackson, S.C., in the fall of 1918. He died that Sept. 26 at the age of 21, just five days after falling ill.
For almost 80 years, two tiny slices of the soldier's lung lay undisturbed in slabs of whiskey-colored paraffin, each smaller than a postage stamp, in institute archives. Then in 1995, institute scientists decided to hunt for the flu virus as a way of demonstrating the value of those archives, which date back to the Civil War.
"I would have suggested at the beginning that the chances of succeeding were very low," says Taubenberger, 36, of Springfield, Va., who holds both a medical degree and a Ph.D in anatomy. The hunt proved very difficult.
"It took a lot of faith and prayer to get it to work," says Reid, 38, of Washington, a research biologist. "We worked on this project for almost two years before we got a usable sample."
Viruses are very simple microbes, basically strings of genetic material wrapped up in a protein coat. The influenza virus has just 10 genes coded in genetic material called RNA; the human body's 100,000 genes are coded in slightly different material called DNA.
The Walter Reed team tracked down the pathogen by hunting for its RNA. Finally, in the summer of 1996, it discovered short segments of viral genetic material. So far, it has identified about 1,800 of 15,000 nucleotide bases -- the letters of the genetic alphabet -- that make up the Spanish flu's genetic code. Eventually, the two scientists hope to sequence them all.
