An increase in mumps outbreaks since 2006 prompted CDC's Advisory Committee on Immunization Practices (ACIP) to unanimously recommend a third dose of MMR vaccines for individuals identified by public health officials as at risk during a mumps outbreak. Many of the outbreaks have been among college students with high rates of immunization. During one presentation, CDC's Mona Marin, MD, explained that the crowded living conditions on college campuses contributed to the recent outbreaks. "Mumps outbreaks continue to be a public health burden, and young adults are at highest risk," she said. "Although half of all outbreaks were less than 10 cases, 13% of outbreaks had 50 or more mumps cases, which accounted for over 80% of all cases." Even with highly immunized populations, one-half of the mumps outbreaks in 2016 were in university settings, as were 40% of all cases.