Hospitalization with varicella and shingles before and after introduction of childhood varicella vaccination in Germany

Abstract

In Germany, one dose of varicella vaccination has been recommended for children aged <24 months since 2004, and 2 doses have been recommended since 2009. Vaccination coverage (VC) is above 80% for one dose and 60% for 2 doses. In this study, data on varicella-and shingles-associated hospitalizations before and after vaccine introduction were assessed. Based on ICD-coded data of the main diagnosis of hospitalized cases from 1995-2012 in Germany, annual age-adjusted and age-specific hospitalization incidences (cases/100,000; HI) were calculated. HI means 1995-2003 (pre-vaccination-period) versus 2005-2012 (post-vaccination-period) were compared. Age-specific trends and annual percentage change rates (APC) were assessed by joinpoint regression. Overall age-adjusted varicella-HI decreased from 3.3/100,000 pre-vaccination to 1.9/100,000 post vaccination. The decline was greatest in regions with the highest VC. The post-vaccination decline was greatest in children aged <1, 1-4, and 5-9 y, who had APCs of-18.2,-27.2 and-15.2, respectively, and significant joinpoints. In all other age groups no post-vaccination joinpoints were detected or they did not lead to a consistent trend. Age-adjusted shingles-HI increased from 8.8/100,000 (1995) to 16.8/ 100,000 (2012). Shingles-HI increased in all age groups with no significant post-vaccination joinpoints, except in children <1 and 1-4 y, where APCs of-5.6 and-3.6 were detected. Varicella vaccination significantly reduced varicella-HI in children below 10 y, but was not definitely related to varicella-HI in older age groups. A consistent increase of shingles-HI began before varicella vaccination was introduced and was not affected by vaccination.