Orlikova 2016.

Methods	Retrospective cohort ‐ case only
Participants	All participants analysed in this study had mumps. Data by age groups were provided. 0 to 14 years old
Interventions	MMR
Outcomes	Clinical complications, and hospital admissions in unvaccinated but also in vaccinated individuals
Notes	Conclusions: this study demonstrates a significant preventive effect of 2‐dose vaccination against mumps complications (orchitis, meningitis, or encephalitis) and hospitalisations for mumps. The risk of complications increases with time interval from vaccination. The most affected age groups were teenagers and young adults.