Increasing vaccinations through an on-site school-based education and vaccination program: A city-wide cluster randomized controlled trial.

Vaccination rates for mumps, measles, and rubella (MMR) and tetanus, diphtheria, pertussis, and polio (Tdap-IPV) fall short of global targets, highlighting the need for vaccination interventions. This study examines the effectiveness of a city-wide school-based educational vaccination intervention as part of an on-site vaccination program aimed at increasing MMR and Tdap-IPV vaccination rates versus on-site vaccination alone among sociodemographically diverse students from Berlin, Germany. The study was a 1:1 two-arm cluster randomized controlled trial, with schools randomly assigned to either the Educational Class Condition (ECC) or the Low-Intensity Information Condition (LIIC). Both received an on-site vaccination program, while students in the ECC received an additional educational unit. Primary outcomes were MMR and Tdap-IPV vaccination rates. In total, 6512 students from 25 randomly selected urban area secondary schools participated. For students providing their vaccination documents on the day of the intervention (2273, 34.9%), adjusted Poisson mixed models revealed significant between-group differences in favor of the ECC (MMR: logRR = 0.47, 95%CI [0.01,0.92], RR = 1.59; Tdap-IPV: logRR = 0.28, 95%CI [0.10,0.47], RR = 1.32). When adjusting for socioeconomic and migration background, between-group differences became non-significant for MMR but remained significant for Tdap-IPV. Findings suggest that educational, school-based on-site vaccination appears to be a promising strategy for increasing vaccination uptake in adolescents.