Influenza poses one of the world's greatest infectious disease challenges. CDC programs protect the United States from seasonal and pandemic influenza. When a new flu virus emerges, with pandemic potential, that can infect people and spread globally, CDC is prepared and ready to respond. Comments on this video are allowed in accordance with our comment policy: http://www.cdc.gov/SocialMedia/Tools/CommentPolicy.html This video can also be viewed at https://www.cdc.gov/flu/video/pandemic-preparedness/influenza-pandemic-preparedness-lowres.mp4