Lack of impact of rotavirus vaccination on childhood seizure hospitalizations in England - An interrupted time series analysis.

Observational studies have linked a reduction in childhood seizures (CS) to the introduction of rotavirus vaccination (RV). England is opportunely placed to explore this due to well-defined introduction, high uptake of RV and centralised Hospital Episodes Statistics recording all admissions. We investigated the association between seizures and vaccine use through interrupted time-series analysis of all CS admissions in children <3 years old (ICD-10 codes; G40-G41, R56.0) during 2007-2017. We did not detect a statistically significant association between the introduction of RV and admission with febrile (p = 0.84), afebrile (p = 0.83) or all CS (p = 0.93), even when limited to peak rotavirus seasonality (March). This is the first ecological study in a country that exclusively uses the monovalent vaccine. Although a negative finding, we would argue that if an effect cannot be detected at this population level then it is unlikely to be clinically or economically significant but generates hypotheses of potential non-specific effects.