This is a follow-up to an earlier study, which looked at the incidence of seasonal rotavirus gastroenteritis (RVGE) hospitalizations in children aged 5 years in Japan from 2009 to 2015. Using the same health insurance claims database and study methods, researchers assessed the incidence of RVGE hospitalizations in children aged 10 years during the rotavirus season (January–June) in Japan from 2009 to 2017, before and after the monovalent and pentavalent rotavirus vaccines were introduced in November 2011 and July 2012, respectively.
The frequency of RVGE hospitalizations in children aged 5 years decreased significantly following vaccine introduction in 2014, consistent with our earlier findings, and the drop was sustained until 2017. During the research period, however, no clear trend for a continual reduction in RVGE hospitalizations was seen in children aged 510 years. Improved RV vaccine coverage may result in a further decrease in severe RVGE in Japan.