Outline: The COVID-19 pandemic has clearly demonstrated the urgent need for a cross-border and structured European mechanism to exchange, organize and access reliable health information between countries, especially in the area of population health. Population health information, defined by data on health status, health determinants and healthcare systems performance, allows for oriented research to increase the knowledge base in Europe and underpin political decision-making. Its exchange requires timely and topical provision of high-quality health information. There are many indirect effects of the COVID-19 pandemic that affect health through various pathways including secondary consequences on health and wellbeing due to delayed prevention, diagnosis and medical treatment. Within the Population Health Information Research Infrastructure (PHIRI) project we measured the impact of COVID-19 on population health through four research use cases demonstrating how a broad variety of routine data can be pooled and/or used for secondary analysis in a distributed way across Europe aiming to facilitate research by making scalable, reproducible methods available. These real-life use cases represent pilot activities for the benefits and added value of an infrastructure supporting federated analysis by bringing together data from different European countries. In over 20 data contributing countries data is mobilized and analyzed in a distributed manner. The use case outputs will be processed in an interoperable way by formalising data models, data management processes and analytical pipelines, all of which are part of the client-server PHIRI federated infrastructure on population health science implemented as here 10.5281/zenodo.6483177 [1]. Aims and component parts: This workshop aims to ensure a better understanding of COVID-19 impacts in specific subgroups and risk settings by conducting research through use cases of immediate relevance to provide actionable outcomes to guide policy makers in preparedness and response scenarios. We will provide insight into the backbone of the analyses, the PHIRI federated research infrastructure (FRI) achievements, in which the governance step-wise approach and the technological solutions will be described. Finally, we will touch ground on the future developments, in particular, the interaction of the PHIRI infrastructure with existing European-wide initiatives like the European Health Data Space for secondary use (EHDS2). Knowledge and capacity developed across Europe is shared in this workshop. The three presentations will focus on selected aspects of COVID-19 impacts on population health as well as the development and implementation of the PHIRI federated approach. The first presentation will be on the FAIRified use cases analysis results focusing on comparisons between countries. This will be followed by a presentation on what the PHIRI FRI has achieved so far. The third presentation looks at the interlinkages and an enhanced version of a fully operative PHIRI infrastructure improving the analytical services. Exchange with the audience will facilitate knowledge and opinion exchange through an interactive Mentimeter poll during the session. Key questions: 1) What are the impacts of COVID-19 in specific subgroups and risk settings compared across European countries? 2) What do population health researchers’ need to enhance their research when reusing individual sensitive data and how PHIRI FRI can help?Links:------[1] https://zenodo.org/record/6483177