Background Measles, mumps, and rubella (MMR) vaccine is a safe combined vaccine that is considered one of the most effective protective measures against three separate diseases: measles, mumps, and rubella (German measles). During 2018, there were reports of an increased number of measles cases in Saudi Arabia and globally. The objective of the current study was to confirm the presence of such an increase among the National Guard population and to assess if mumps and rubella were also affected.

Methods Communicable diseases are regularly reported from the National Guard population in all regions to the public health section of the Infection and Prevention Control (IPC) department at Riyadh. Retrospective review of prospectively collected information about the three diseases prevented by MMR was conducted in 2019. This covered the period between 2008 and 2018.

Results During the study period, a total of 48 patients with measles, 84 with mumps, and 20 with rubella had been reported to the IPC department. Compared with the previous 10 years, the number of patients with measles increased from an average of 3.7 to 11 (197% increase). Compared with the previous 10 years, the number of patients with mumps increased from an average of 5.6 to 28 (400% increase). Compared with the previous 10 years, the number of patients with rubella increased from an average of 1.8 to 2 (11% increase).

Conclusion We are confirming an outbreak of both mumps and measles. This may indicate that the increase is related to a problem with MMR coverage or effectiveness. Further research is required to confirm the possible causes of this outbreak: missing immunization, shortness of vaccine, misconception about the link between the MMR vaccine and autism, vaccine-induced disease, and pockets of unvaccinated immigrants. Additionally, there is an urgent need to increase public awareness of the MMR vaccine.