Controlling Mumps During an Outbreak

The last decade has seen recurrent outbreaks of mumps in the U.S. on college campuses, surprisingly involving populations thought to be protected by exceedingly high immunization rates. These outbreaks have led public health authorities to wonder if providing an additional dose of the measles–mumps–rubella (MMR) vaccine might be beneficial in outbreak control. An outbreak occurring in the 2015–2016 academic year at the University of Iowa allowed study of both this question and the durability of immunity following two doses of MMR vaccination. After the mumps outbreak was recognized in July 2015, the university held mass-vaccination clinics on campus for students younger than 25 years to provide a third MMR dose to students who had previousl…