U.S. President Barack Obama applauds his audience during an event held in observance of World AIDS Day at the White House in Washington December 4, 2013 580 × 361 U.S. President Barack Obama applauds his audience during an event held in observance of World AIDS Day at the White House in Washington U.S. President Barack Obama applauds his audience during an event held in observance of World AIDS Day at the White House in Washington December 2, 2013. REUTERS/Kevin Lamarque