The "Morbidity and Mortality Weekly Report" ("MMWR") Series is prepared by the Centers for Disease Control and Prevention (CDC). Data presented by the Notifiable Disease Data Team and 122 Cities Mortality Data Team in the weekly "MMWR" are provisional, based on weekly reports to CDC by state health departments. This issue of "Morbidity and Mortality Weekly Report" includes the following reports: (1) Outbreak of Meningococcal Disease Associated with an Elementary School--Oklahoma, March 2010 (Kristy Bradley, Lauri Smithee, Thomas Clark, Henry Wu, Raydel Mair, Brian Harcourt, Leonard Mayer, Susanna Schmink, Christopher Paddock, Sherif Zaki, and Steven Grube); (2) HIV, Other STD, and Pregnancy Prevention Education in Public Secondary Schools--45 States, 2008-2010 (Laura Kann, Nancy Brener, Timothy McManus, and Howell Wechsler); and (3) Influenza Outbreaks at Two Correctional Facilities--Maine, March 2011 (Sara Robinson, Peter Smith, Stephen D. Sears, Joseph Shubert, Carrie Reed, and Susan E. Manning). Announcements and QuickStats are also included. Individual reports contain figures, tables and references.