Incidence of Type 1 Diabetes in Relation to Exposure to Rotavirus Infections in Pre- and Post-Vaccine Birth Cohorts in Finland

Objective To explore the incidence of type 1 diabetes in children in relation to exposure to rotavirus infections.

Research Design and Methods A nationwide register-based ecological study on the 1995–2015 birth cohorts in Finland, comparing those born before and after the national implementation of the rotavirus vaccine in 2009.

Results When comparing the pre-vaccine 2001–2005 birth cohorts to the post-vaccine birth cohorts, the number of children exposed to rotavirus infection by the age of 5 years decreased from 2522 per 100 000 children (2.5%) to 171 per 100 000 children (0.2%), whilst the incidence of type 1 diabetes in those aged below 5 years decreased from 71.5 to 54.4 per 100 000 person-years (incidence rate ratio 0.79, 95% CI 0.71 to 0.86).

Conclusions At the population level, a decrease in exposure to rotavirus infections was associated with a decrease in the incidence of type 1 diabetes in young child.