Spanish Flu Rises Again

Nature reports on a CDC researcher's reconstruction of the Spanish Flu, killer of a hundred million people back in 1918 according to some estimates.

When they used the strain to infect mice they found it was extremely virulent, and after 4 days had generated 39,000 times more virus particles in the animals' lungs than a modern flu strain. "I didn't expect it to be as lethal as it was," says Tumpey.

Neither did those hundred million people...