2009 swine flu pandemic in the United States

The 2009 flu pandemic in the United States was caused by a novel strain of the Influenza AH1N1 virus. There is no evidence that it is endemic to pigs or of transmission from pigs to people; instead, the virus spreads from person to person. From April 12, 2009 to April 10, 2010, the CDC estimates there were 60. 8 million...