New flus have appeared consistently over the years. So what makes this flu so scary?
Throughout history, every new flu strain has been scary because it catches the human immune system unprepared. The death toll from a new flu is always higher. But H5N1 is extra scary because it resembles the most infamous flu virus of all time, the 1918 Spanish flu strain, the one that infected half the world’s population, killing more than 40 million people. For years, the Spanish flu virus was a mystery until scientists dug through old U.S. army autopsy samples and collected enough of the virus to genetically reconstruct it. What they found was an avian flu that has a lot in common with today’s H5N1. Michael Osterholm, an infectious disease expert at the University of Minnesota says, “H5N1 is very similar to, if not a kissing cousin to, the H1N1 virus that we saw in 1918. Not only does it act the same way with the kind of immune response it elicits, it is a lethal killer in animals and humans.” Most of the human cases have been in Southeast Asia. But cases have also turned up in Turk
