Long-Term Consequences of COVID-19 Disease and Vaccination: The BMG-Funded Research Projects prevCOV and COVYOUTHdata Focused on Post-COVID and Post-Vac Syndrome

The COVID-19 pandemic was not only responsible for immediate impacts on individual health, but also for a large number of long-term health effects that are now grouped under the terms Post-COVID Syndrome (PCS) or Long COVID. In addition to these known phenomena, similar symptoms that are occasionally observed after COVID-19 vaccinations are described using the term Post-Vac Syndrome. Both syndromes are characterised by persistent and often nonspecific complaints, which make diagnosis, treatment, and care considerably more difficult. Two research projects funded by the Federal Ministry of Health (BMG) – prevCOV and COVYOUTHdata – are addressing this issue. The aim is to describe the disease epidemiologically in adults, children, and adolescents and to improve treatment by creating precise case definitions, identifying risk and prognostic factors, and optimising care. The methodology for both projects is based on systematic literature research and the linking and analysis of COVID-19 vaccination data, routine statutory health insurance data, and supplementary primary data in a manner conform with data protection law. This article describes the methodological foundation of both projects, in particular the data infrastructure, linkage possibilities and planned analyses, and discusses the relevance of such an approach for future population-based studies in Germany.