HHS Secretary Kathleen Sebelius announced the administration's new initiative to combat the flu on Whitehouse.gov this weekend. The administration hopes to encourage vaccination through an innovative viral Facebook application, I'm a Flu Fighter!, which lets people tell their friends they got the flu shot and challenges them to do the same. The app was developed by Ben Reis of Children's Hospital Boston and Harvard Medical School, director of the HealthySocial project, which aims to leverage social media to spread positive health behaviors. Perhaps the power of positive peer pressure will succeed in increasing vaccination rates amongst Americans, who just a few short months ago seemed very anxious about there not being enough vaccine for everyone...