Impact of Rotavirus Vaccination on Childhood Hospitalizations for Seizures: Heterologous or Unforeseen Direct Vaccine Effects?

There is a growing interest in the possible relationship between rotavirus (RV) vaccine and hospitalizations due to childhood seizures. We explored variation in hospitalization rates after 9 years of vaccination against pre-vaccination period for children <5 years of age from Galicia (Northwest Spain) before and after the introduction of the RV vaccines. Hospitalization rates for childhood seizures in Galician children were compared before and after RV vaccine introduction (in 2007) using different statistical approaches, including time series analyses. Our study cohort totaled 7,712 children <5 years of age admitted to hospital between 2002 and 2015 for "all kind of childhood seizures". Hospitalization rates decreases steadily with reductions ranging from 22.3% (95% CI: 15.0-29.1) in 2008, to 50.9% (95% CI: 45.5-55.7) in 2014, and significant results were also observed for <1, 1, and 2-year-old children in comparison with pre-vaccination period hospitalization rate. Regression models indicate a negative association between RV vaccination and hospitalizations for all kind of seizures. In addition, time series analyses are consistent with this finding and predict that vaccination coverage will affect hospitalization rates for "all kind of seizures" after 9 months. The results strongly support that RV vaccination has significantly reduced hospitalization rates due to childhood seizures.