National campaign for measles vaccination, verification, catch-up, and response among children and adolescents under 18 years

Abstract

In 2023, Morocco experienced a nationwide measles outbreak. From October 2023 to March 2025, a national campaign of measles vaccination, verification, catch-up, and response was launched, targeting children and adolescents under 18 years of age. This study aims to assess and comprehensively describe the campaign’s impact on measles vaccination coverage, highlighting the need to address post-COVID-19 immunization disruptions. Verification rates, incompleteness levels, and catch-up coverage were estimated using national campaign data, and regional disparities were assessed using descriptive statistics, box plots, and principal component analysis (PCA). Results were compared with the international literature on efforts to control measles, particularly in low-and middle-income countries (LMICs). The overall campaign coverage was high, with an average verification rate of 96.64%, particularly strong in the Oriental region, where the rate exceeded 100%, likely reflecting denominator underestimation and/or cross-boundary vaccination flows. However, substantial inter-regional disparities were observed in catch-up rates, ranging from 79.05% in Eddakhla-Oued Eddahab to as low as 16.12% in Guelmim-Oued Noun. These disparities may reflect differences in geographic accessibility, health system capacity, and sociodemographic factors across regions. The national incompleteness rate stood at 15.69%, indicating significant room for improvement. Service disruptions resulting from the COVID-19 pandemic contributed to the decline in immunization rates before the campaign. While the campaign was associated with improved verification and strengthened measles vaccination coverage, regional disparities and incomplete coverage persisted. In the quest for sustainable measles control, Morocco will require targeted interventions, including school-based vaccination, digital reminder systems, and enhanced community engagement, to achieve its elimination goals, informed by best practices from other parts of the world.