Large cohorts, with potentially millions of participants, are needed to understand the genetic and molecular signatures of diseases, and they provide a cornerstone for the creation of personalised treatments. The ELIXIR::GA4GH Strategic Partnership will facilitate the responsible sharing of these sensitive data across Europe in order to help create virtual cohorts with tens of millions of participants. In this session we will describe the complimentary activities that are carried out by both organisations with a focus on secure data archival, federated data discoverability, authorised data access, and distributed data analysis.