Is the world ready for a killer, autumn wave of swine flu?
Infections may be winding down in Mexico and causing fewer deaths worldwide than feared, but what’s now keeping health officials awake at night is the possibility that a more virulent version will come roaring back and kill millions. Flu pandemics historically come in waves, often getting worse as they go. The deadly one of 1918, which was also the last H1N1 pandemic, did just that. “So did pandemics in 1890, 1847, 1781 and others,” says Lone Simonsen (cq) of George Washington University, Washington, D.C., who has studied the progress of the 1918 pandemic. The 1918 flu started with a mild wave in March, followed by a deadly second wave later in the year. For the 2009 virus to follow the same path, two things need to happen: The virus has to spread readily enough in humans that it does not fizzle out, and it needs to mutate to a nastier form capable of killing more people. It seems unlikely that this virus will simply fizzle out, as it has already managed to persist for months. Mike Wor
