Josephine van Dongen

1 General introduction 17 in the new endemic state, including a risk-benefit analysis. In chapter 4 , we compare a vaccinated and unvaccinated cohor t of medical risk infants fol- lowed until 18 months of age for the occurrence of acute gastroenteritis.Vaccine effectiveness against severe rotavirus acute gastroenteritis will be assessed using time-to-event analysis.Vac- cine impact on rotavirus hospitalization, vaccine effectiveness against rotavirus gastroenteritis of any severity and against all-cause acute gastroenteritis will also be determined. In order to guide clinical recommendations subgroup analyses are performed. Safety and tolerability of human rotavirus vaccination among infants with MRC will be repor t- ed in chapter 5 , based on active surveillance for (serious) adverse events following childhood vaccinations including against rotavirus. It is known that premature infants in par ticular can experience more frequent and specific adverse events.The analysis therefore focuses primar- ily on premature infants. Infants with other medical risk conditions are analysed separately. In chapter 6 the potential non-specific effects of rotavirus vaccination will be assessed by measuring effects on acute respiratory tract infections, atopy and all-cause hospitalization (excluding hospitalizations for acute gastroenteritis) within the RIVAR cohor t. We evaluate the feasibility of this selective rotavirus vaccination program implemented in secondary and ter tiary pediatric care in chapter 7 . Feasibility will be evaluated based on achieved vaccination coverage, and by exploring views and experiences of involved health care providers and parents of medical risk infants. In chapter 8 we synthesize the key findings of the RIVAR project and relate them to existing evidence. Fur thermore, recommendations for fur ther perspectives in research and clinical practice are provided.