[Mumps makes a comeback].

After vaccination of Dutch children against mumps started in 1987 through the National Immunisation Programme the incidence of mumps decreased greatly. However, outbreaks of mumps have been occurring since the end of 2009, especially among students. We describe a vaccinated 20-year-old woman with uncomplicated mumps, a vaccinated 20-year-old student with mumps orchitis, and an unvaccinated 14-year-old boy who developed one-sided permanent deafness as a complication of mumps.