BMJ open published the study protocol for the HELICON data linkage.

This protocol aims to provide a case study for linking highly sensitive individual-level information. We describe the data linkages between health surveillance records and administrative data sources necessary to investigate social health inequalities and the long-term health impact of COVID-19 in Belgium. Through a linkage between Sciensano, Statistics Belgium and InterMutualistic Agency, the dataset will cover inpandemic and postpandemic health information between July 2020 and January 2026, as well as sociodemographic characteristics, socioeconomic indicators, healthcare use and related costs. 

The full publication is available via 

https://bmjopen.bmj.com/content/13/5/e069355