Background: Since 2004 a single varicella vaccination for all infants aged 11-14 months has been recommended in Germany and since 2009 a second dose at the age of 15-23 months is recommended. Vaccination coverage after 24 months rose from 43% in 2006 to 87.5% in 2012. A mandatory notification system was introduced in the New Federal States (NFS) between 2002 and 2009 and nationwide in 2013. A national sentinel system has been in place since 2005.
Objective and method: We analyzed both data sources to describe the varicella epidemiology related to vaccination coverage after initiation of routine childhood varicella vaccination and to evaluate both notification systems regarding informative value and data quality. We looked at trends, age distribution and incidences using Microsoft Excel and Stata12. Vaccination coverage data were available from health insurance claims data.
Results: By 2013 a decrease of cases/medical practice/month from 3.47 to 0.43 was observed. The incidence in the NFS declined from 32 to 12 out of 100,000. Sentinel and mandatory notification data showed the largest decrease among the 1-4 year-olds (-94 and -90% resp.). In 2014, varicella incidences increased in all age groups, but not the cases/medical-practice/month by age in the sentinel.
Discussion: Increasing vaccination coverage and decreasing varicella cases demonstrate the success of routine childhood varicella vaccination. Mandatory notification data allow incidence calculation; The sentinel system has been providing more detailed information about vaccination status, better data quality and continuous national data since 2005, irrespective of the Infectious disease protection act. Trends and age distribution can be continuously calculated, whereas the nationwide mandatory data collected in the short period since April 2013 can only be evaluated to a limited extent.
Keywords: Epidemiology; Mandatory notification; Sentinel; Vaccination; Varicella.