Universal Mass Vaccination Against Rotavirus Gastroenteritis Impact on Hospitalization Rates in Austrian Children

Background: Since July 2007, rotavirus vaccinations have been subsidized in Austria for all children from the seventh week up to the sixth month of life. Vaccination coverage over the whole period was 72% with an increase to 87% in 2008. Methods: In a sentinel network including 11 pediatric hospital wards in Austria, data of children up to 15 years of age and hospitalized due to rotavirus gastroenteritis between January 2001 and December 2008 have been collected. Results: The hospitalization rates of children up to 12 months of age with rotavirus gastroenteritis were 2066 x 10(-5) between 2001 and 2006 and decreased to 631 x 10(-5) in 2008. For children between 12 and 24 months of age the hospitalization rate decreased from 1822 x 10(-5) (2001-2006) to 1456 x 10(-5) in 2008. In children aged 2 to less than 5 years, incidence rates were 436 x 10(-5) (2001-2006) and 461 x 10(-5) in 2008. In older children, the hospitalization rates remained unchanged. In the target population for the RV-vaccine, a decrease of hospitalization rates due to rotavirus gastroenteritis of 74% was observed compared to the era before the introduction of the vaccine. The field effectiveness of the vaccine was estimated between 61% and 98%, depending on assumptions about the vaccination status. Conclusions: Within 18 months, the universal mass vaccination program against rotavirus led to a substantial decrease in the hospitalization rates of the target cohort of the immunization program in Austria.