Josephine van Dongen

8 Summary and general discussion 193 rotavirus vaccination in medical risk infants. So far, inconclusive evidence is repor ted on the overall benefit of (live-attenuated) childhood vaccines on non-target diseases 54,55 and the mechanisms that could mediate the non-specific effects have not yet been fully elucidated. Therefore, fur ther evidence is needed before these effects could be considered for inclusion in cost-benefit analyses. For rotavirus, the combined data from the rotavirus vaccine phase III efficacy trials analyzed with non-AGE acute hospitalization or hospitalization for respiratory infection as outcome, should be suitable to provide more definite answers on the protection of rotavirus vaccination against non-target diseases. Hospital-based targeted vaccination The hospital-based targeted rotavirus vaccination strategy resulted in suboptimal overall vaccination coverage and several hurdles were encountered as identified in the survey and in- depth interviews. Parents of medical risk infants were insufficiently reached and providing quality of care by timely and personal vaccine counseling proved difficult to achieve for all eligible infants. Among the cohor t-study par ticipants however, better counseling was feasible with the aid of a dedicated RIVAR researcher and resulted in a much higher vaccination coverage of 85%. It is however unlikely that this level of suppor t could be maintained in a national roll-out of this hospital-based vaccination strategy. At the time of writing, only two countries, Croatia and Spain, have implemented targeted vaccine programs for rotavirus vaccination. 56,57 No estimates on vaccination coverage or effectiveness from these countries have been published. Alternative strategies to deliver rotavirus vaccination to medical risk infants therefore need to be considered. In the Netherlands the national immunization program is invested with well- baby clinics and executed by youth HCP. Using this infrastructure for rotavirus vaccination of infants with MRC is possible. However, due to (prolonged) hospital stay and frequent post- discharge outpatient visits, many MRC infants do not receive care by youth HCP within the tight age restrictions of first dose administration of rotavirus vaccine. Therefore, some kind of cooperation between youth HCP and hospital care will be necessary, which already proved difficult to implement in practice. 14 Implications for vaccine policy and future research The two main aims of the RIVAR project were to assess feasibility and effectiveness of a selective rotavirus vaccination strategy targeting infants with MRC. The achieved reduction of severe rotavirus acute gastroenteritis was limited and the feasibility of selective hospital-based vaccination proved suboptimal. In this paragraph, I will weigh protective effects (direct, indirect and non-specific), safety profile, different vaccination strategies and cost-effectiveness in order to arrive at recommendations for future rotavirus vaccination policy for medical risk infants.