Mumps Resurgent
Since Mumps vaccine was introduced there has been a significant drop in new cases, as seen in this graph.

However in 2006 a resurgence of mumps ocurred in the upper central USA. There was only moderate uptake of a second dose of mumps vaccine putting adolescents and young adults at risk. This shows a similar pattern to the Measles outbreak in South Texas twenty years ago which lead to recommendation of a second dose of vaccine in middle school. The difference was that 98%+ of the Texas students had received their vaccine dose as recommended. This was not the case with the mumps vaccine. Part of the problem is anxiety anong parents about supposed ill effects from vaccines, grossly overestimated but pushed by the media for its value as a scary story. Future studies will help to evaluate the national vaccine policy, including whether the administration of a second dose of MMR vaccine at a later age or the administration of a third dose would provide higher or more durable immunity.
N Engl J Med 2008;358:1580-9.