How Pandemics Have Reshaped the Respiratory Virus Data Landscape in Europe: Scoping Review.

Background: Acute respiratory infections caused by influenza, respiratory syncytial virus (RSV), and SARS-CoV-2 remain a major public health challenge in Europe. Although surveillance systems for these pathogens are well established, the past 2 decades have seen a rapid diversification of data streams supporting surveillance and research. This expanding data landscape, combined with fragmentation across institutions, sectors, and countries, may limit timely evidence synthesis and effective public health decision-making. Objective: This scoping review aimed to identify and characterize data sources used for surveillance and research on influenza, RSV, and SARS-CoV-2 in Europe over the past 20 years, and to examine their evolution over time, their alignment with research objectives, and geographic variation in data availability and use. Methods: We conducted a scoping review using an objective-driven analytical framework. Empirical reports published between January 2005 and September 2025 were identified in MEDLINE, Web of Science, and Embase. Eligible reports focused on influenza, RSV, or SARS-CoV-2 and included data from 12 European countries. Clinical and interventional studies were excluded. Reports were classified according to 4 research objectives: epidemiological monitoring, evaluation of interventions, assessment of disease burden and health outcomes, and analyses of population adherence and trust toward public health measures. Data sources were grouped into 9 categories, including surveillance systems, electronic health records (EHRs), registries, claims, surveys, digital, environmental, integrated datasets, and others. Results: A total of 2564 empirical reports were included. Over time, respiratory virus research relied on an increasingly diverse set of data streams. While surveillance systems remained central, particularly for epidemiological monitoring, their relative dominance declined. From 2020 onward, there was a marked expansion in the use of EHRs, registries, claims data, digital sources, and linked or integrated datasets, alongside increased use of open-access data. Data source use varied by research objective: surveillance data predominated in monitoring and intervention evaluation; EHRs in studies of risk factors and treatment effectiveness; surveys in seroprevalence and public trust analyses; and claims data in assessments of economic burden. Substantial geographic disparities were observed. Northern European countries more frequently used linked and multisource datasets, whereas Southern Europe relied more often on open-access or single-source data. Conclusions: This scoping review provides a multipathogen, cross-country mapping of data sources for respiratory virus surveillance and research in Europe over 2 decades, applying an innovative objective-driven framework. Unlike prior reviews focused on single pathogens or data types, it offers a consolidated, comparative perspective based on 2564 reports to inform public health decision-making. The COVID-19 pandemic accelerated innovation in data generation and access, but progress remained largely centered on SARS-CoV-2, while structural fragmentation continues to limit timely, integrated data across Europe. Strengthening preparedness will require interoperable infrastructures, federated analysis platforms, sustainable funding for surveillance innovations, and cross-sectoral data sharing.