"So the CDC and the WHO are releasing statements left and right, upping the alert levels and saying that the swine flu may be headed towards a global pandemic scale. It's not particularly deadly (outside of Mexico for some reason) so a lot of people wonder why all the fuss. In layman's terms, the fuss is due to the fact that it's a new virus, one that managed to cross the animal to human barrier (a feat) and then transmit human to human (a major feat). It's a combination, they say, of 4 different viruses: swine, avian, and 2 human strains. People naturally have no real built up immunity to it, which is where a great deal of risk comes in. On top of that, influenza is notorious for it's ability to mutate quickly, and so any unknown version of it that can do things like jump from animals to humans is potentially a huge risk."
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