Josephine van Dongen

4 Rotavirus vaccine effectiveness 95 A. B. Figure 1. Schematic outline of study data collection and procedures. Abbreviations: AGE = acute gastroenteritis. A. Implementation of a hospital-based selective rotavirus vaccination program: A screening log was recorded for infants with at least one of the qualifying MRC. Exclusion criteria were; known hypersensitivity to the vaccine components, history or predisposition of intussusception and/or diagnosis of severe combined immunodeficiency syndrome (SCID). During the pre-implementation period, eligible infants received standard of care only without rotavirus vaccination. Following implementation, eligible infants were offered rotavirus vaccination free of charge. Rotavirus vaccination status was documented in the screening log for each eligible infant.We also logged any serious adverse reaction as documented in the medical char t. Hospitals continued screening and vaccination until the end of the project in November 2019.The first dose human rotavirus vaccine (HRV) was administered by a healthcare professional at the study site between six and 14 weeks of age.The second dose was by default administered by parents at home, following detailed instructions, with a minimal interval of four weeks and no later than 23 weeks and 6 days of age. Alternatively, the second dose could be delivered at the site and administered by a healthcare professional. B. Before-after cohor t study: Eligible infants were not approached for par ticipation in the cohor t study if parents were not proficient in Dutch language, if the child was in custody or in an unstable home situation, if the infant had a poor medical prognosis, or if the infant was discharged from follow–up (including transfer to another non-par ticipating hospital) before six weeks of age. Following informed consent, parents received a baseline questionnaire on household composition, socio-economic status and pregnancy, followed by shor t monthly questionnaires and a final questionnaire at 18 months of age. The monthly questionnaire consisted of seven items on respiratory and gastrointestinal symptoms during the past month, received vaccinations of the National Immunization Program (NIP) and rotavirus and solicited adverse events in the seven days following vaccination, type of feeding and daycare attendance. The final questionnaire at 18 months contained a modified quality of life questionnaire. Finally, trained research staff collected data from the par ticipating child’s hospital medical record at six weeks, five and 18 months of age, including rotavirus vaccination status and dates of vaccine administration, information on all hospitalizations, suppor tive therapy, medical treatment and complications