>"Swine flu, or H1N1, moved from pigs to people in 2009 and caused a pandemic. It is now a relatively common type of flu, and most people have some immunity. Learn more here."
>"Swine flu, or H1N1, moved from pigs to people in 2009 and caused a pandemic. It is now a relatively common type of flu, and most people have some immunity. Learn more here."