Is bird flu this fall’s Y2K? That’s basically what Marc Siegel wrote on Slate in mid-September…

Yet the science behind all the worry is questionable. It rests on the unproven claim that the avian flu will develop exactly like the strain that caused the flu pandemic of 1918. A March 2004 article in Science showed that the 1918 flu—which infected close to a billion people and killed 50 million or more—made the jump from birds to humans through a slight change in the structure of its hemagglutinins, the molecules by which the virus attaches itself to body cells….

The current bird flu, however, has a different molecular structure than the 1918 bug. And though it has infected millions of birds, there is no direct evidence that it is about to mutate into a form that would transmit from human to human. In isolated cases, food handlers in Asia have gotten sick, but that doesn’t mean that a wildly lethal mutation is about to occur….

Even if the worst-case scenario does occur and the virus mutates, there is no current indication that it will spread the way the Spanish flu did in 1918. That disease incubated in the World War I trenches before it spread across the world, infecting soldiers who were exhausted, packed together in trenches, and lacked access to hygiene. These conditions were an essential breeding ground for the virus. Today, there is no way a huge number of people would be packed together in WWI-like conditions….