The impact of rotavirus vaccination in Italy: an eleven-year (2009-2019) nationwide analysis

Although the positive effects of the introduction of rotavirus (RV) vaccination in Italy, a national updated analysis of its effect in still lacking to date. This study aims to analyze the implementation of rotavirus vaccination in Italy, evaluating its impact on discharges for acute pediatric gastroenteritis. A retrospective analysis including hospital discharge records and data on vaccination coverage for children aged 0-71 months from 2009 to 2019 was conducted. We examined trend in hospital discharge standardized incidence before and after vaccine introduction using a negative binomial mixture model with fixed effects to evaluate the impact of universal vaccination. The percentage of vaccination coverage increased over the years, from < 5% between 2009 and 2013 to 26% in 2017. After the inclusion to the National Im-munization Plan, in 2019 over 70% of children received the vaccine. In the first phase (2009-2013), the standardized incidence of discharges was 16.6/100,000 inhabitants; it decreased in the second phase (2014-2017) reaching 14.1/100,000 inhabitants. During the third phase (2018-2019) it significantly decreased to 9.9/100,000 inhabitants. In this phase, about 15% of the estimated hospital discharges were avoided compared with those estimated using the first phase data. The implementation of rotavirus vaccination reduced acute pediatric gastroenteritis incidence discharges in children aged 0-71 months. Further efforts are needed to continue monitoring the vaccination effect over time and to increase vaccination coverage. KEY MESSAGES: • The implementation of Rotavirus vaccination in Italy resulted in a reduction of acute pediatric gastroenteritis. • Further efforts are needed to maintain high vaccination coverages, thus reducing the negative impact of rotavirus disease.