Outbreaks due to measles, mumps, rubella and varicella in schools: a systematic review of the literature.

Several decades into routine pediatric vaccinations worldwide, many vaccine-preventable diseases (VPDs) remain endemic and cause outbreaks with serious morbidity and fatalities, even in countries with long-term implemented pediatric vaccination programs. Schools play a critical role during childhood and adolescence not only for educational purposes, but also for the socialization and overall well-being of children and adolescents. Participation in most school activities usually requires close proximity and interaction among students in indoor settings, which facilitates the transmission of several VPDs. We reviewed 57 articles presenting original data on measles, mumps, rubella, and varicella outbreaks in schools published between 2000 and June 2, 2025. Most published outbreaks occurred in schools in high-income countries. Among all school outbreaks studied, measles outbreaks were by far the most important, in terms of number of published outbreaks and number of school-related cases, followed by mumps and varicella outbreaks, while rubella outbreaks were rare. In addition, measles outbreaks had the highest attack rates (up to 51%). No fatalities were recorded. Except for mumps, and to a lesser extent for varicella, which often occurred in highly vaccinated school populations, outbreaks of measles and rubella were predominantly observed among unvaccinated or partially vaccinated students and staff. Educational and social activities among students were frequently disrupted while on several occasions schools served as amplifiers of transmission of infection in the communities. Given the stagnation of vaccination rates against several VPDs in many countries worldwide, school outbreaks may occur more frequently and put more children and adolescents at risk.