December 20, 2011
Health workers slaughter all the chickens at the wholesale poultry market in Hong Kong in 2008 after three dead chickens tested positive for bird flu. The U.S. government asked scientists Tuesday not to reveal all the details of how to make a version of the deadly bird flu that they created in labs in the U.S. and Europe.
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The U.S. government paid scientists to figure out how the deadly bird flu virus might mutate to become a bigger threat to people — and two labs succeeded in creating new strains that are easier to spread.