Josephine van Dongen

Chapter 6 150 Univariate 95% CI Multivariate estimate Lower 95% CI Upper 95% CI IRR for ARI until 11 months # 1.10 0.99-1.22 1.03 0.92 1.15 IRR for eczema until 6 months # 0.99 0.71-1.41 0.91 0.62 1.33 IRR for eczema until 11 months # 0.96 0.73-1.24 0.89 0.66 1.19 * Adjusted for : gestational age, presence of congenital disorder, type of hospital care and seasonality. # Adjusted for : gestational age, daycare attendance, parental educational level, presence of sibling in the household, vaccinated according to NIP program and seasonality. Abbreviations: HR = hazard ratio, IRR = incidence rate ratio, RR = relative risk, CI = confidence interval In sensitivity analyses we observed that the non-specific effects estimates were closer to one and non-significant when restricting to the six or eleven months of age for all non-specific effect outcomes, table 3 . Restricting to acute hospitalizations for infectious diseases resulted in an adjusted HR of 0.96 (95%CI 0.58;1.62). Discussion This quasi-experimental prospective study assessed the potential non-specific effects of rotavirus vaccination among 1215 infants with medical risk conditions. Our results suggest that HRV does not offer significant protection against non-target diseases leading to acute hospitalization, or result in reduced incidence of ARI or atopy up to 18 months of age. Non-specific effects of (live-attenuated) vaccines are increasingly being studied. Currently, 22 trials are being performed or completed on the potential protective effect of BCG vaccination against COVID-19 disease. 22 For rotavirus vaccines however, there has been very little research into non-specific effects despite their availability and widespread use for more than a decade. While some promising results of beneficial non-specific effects, in par ticular for BCG vaccine are available, 1,4,9,19 other studies repor t contradictory and less convincing results. 12–14,27 The results of our study add to the growing body of evidence hinting towards absence of non-specific effects, at least for rotavirus vaccines. Opposite to our result, a reduction in acute hospitalization due to non-target diseases after rotavirus vaccination was repor ted in a previous study from the United States. 24 As a secondary analysis, this study compared hospitalization rates in the 60-day post-vaccination window for rotavirus vaccinated and unvaccinated infants, excluding hospitalizations coded as rotavirus gastro-enteritis. A reduction of 31% (95%CI 27-35%) was repor ted. However, coding for rotavirus hospitalizations is known to be incomplete. 28 By including hospitalizations for gastro-