Secular trends in vaccination rates among school beginners in Baden-Wuerttemberg, 1987–2014

Abstract

Introduction Mandatory health investigations of children before school entrance in Germany allow the surveillance of vaccination rates in subsequent age cohorts of school beginners at the age of school entrance (about six years). The aim of the study presented here was an overview of secular trends in vaccination rates among children before school entrance in the State of Baden-Wuerttemberg. Methods Since 1987 data on vaccination rates were collected in school entrance investigations by the health offices in the whole country of Baden-Wuerttemberg, which is located in the Southwest of Germany. Analyses of secular trends in vaccination rates by the Baden-Wuerttemberg State Health Office included data on vaccinations against diphtheria, poliomyelitis, tetanus, measles, mumps, rubella, Haemophilus influenzae, hepatitis B, pertussis and varicella. The annual vaccination rates were determined for about 100,000 per year in the country of Baden-Wuerttemberg and visualized in time series in order to describe secular trends of the different vaccinations. Results The percentage of children with a written documentation of the vaccinations they received was 90% > 92% compared to all children investigated. The highest vaccination rates during the whole observation period were observed for the vaccinations against diphtheria, tetanus and poliomyelitis. Vaccination rates against pertussis covered 10–20% of the children until 1996 and increased since then to 93% in 2014 after the introduction of acellular pertussis vaccines and recommendation of the vaccination for all children. The vaccination rates against measles, rubella, hepatitis B and varicella mainly reflect the development of recommendations of the German Standing Committee on Vaccination (STIKO). So the second vaccination against measles was recommended until 2000 at the age of 4 to 5 years. This recommendation was changed 2001 to the age of 1 to 2 years, which led to an increase in the corresponding vaccination rates to almost 95% in 2014. The general recommendation of the vaccination against varicella for children was introduced in 2004 and subsequently the vaccination rates among school beginners increased and reached 77% in 2014. This is still below the rates of other vaccinations introduced decades before. Conclusions The regular collection of data on vaccinations in school entrance health investigations allows a continuous surveillance of vaccination rates based on 90–92% of all school beginners. The interpretation of secular trends has to take into account changes in the recommendations of the German Standing Committee on Vaccination as well as potential changes in the age of the children at time of investigation. The time series can indicate infections risks due to missing vaccinations among adolescents and adults, in case these age groups did not receive missing vaccinations after school entrance. Therefore the regular collection of these data from vaccination documents of school beginners should be continued for a long-term surveillance by public health offices.