Benefits of childhood vaccines in ecological studies focusing on Germany: a scoping review protocol.

INTRODUCTION: General statements that vaccinations are among the most important preventive measures in medicine are common in public health guidance. While the efficacy of individual vaccines is well established through randomised controlled trials and observational studies, ecological studies at the population level can provide complementary insights into the relative historical contributions of different childhood vaccinations to reductions in morbidity and mortality. To date, there has been a lack of systematic reviews of such comparative studies, especially with a focus on Germany. The aim of this scoping review is to map the state of research on ecological studies that compare the relative contribution of different childhood vaccinations to reducing morbidity and mortality, with a focus on reported data from Germany in an international comparison. A more precise scientific and public communication about vaccinations strengthens confidence in evidence-based vaccination recommendations. METHODS AND ANALYSIS: This scoping review follows the Joanna Briggs Institute methodology for scoping reviews. Reporting will be in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Extension for Scoping Reviews (PRISMA-ScR). A comprehensive search will be conducted in MEDLINE via PubMed, Embase via Elsevier, Web of Science, Scopus via Elsevier and Google Scholar, supplemented by grey literature sources. Studies will be selected and data charted by at least two independent reviewers using the Population/Concept/Context (PCC) framework. Results will be synthesised descriptively and presented thematically. ETHICS AND DISSEMINATION: No ethical approval is required as this is a secondary analysis of published data. The findings will be disseminated through publication in a peer-reviewed journal and as part of the first author's doctoral thesis. The protocol is registered on the Open Science Framework (https://doi.org/10.17605/OSF.IO/4FH3X).