Issue: Individual solutions on national level

The backends (= data processing and storage in the background; counterpart of the frontend, which describes the visible surface of apps) behind the different national Tracing Apps currently do not exchange information. This is unfortunate, as neither the COVID-19 virus nor EU citizens enjoying their freedom of movement stop at national borders. It would be preferable that Tracing Apps developed and deployed at national level remain functional even when users travel to another EU member state. In order to ensure maximum effectiveness, it is essential that users don’t have to download different national apps when travelling across Europe.

Potential solution: Technical specifications for cross-border exchange of information

To come up with a potential solution, the EU Member States, supported by the EU Commission, recently agreed on a set of technical specifications to ensure a safe exchange of information between national Tracing Apps. This set of technical specifications was elaborated by the eHealth Network, a voluntary network set up under article 14 of Directive 2011/24/EU providing a platform of Member States' competent authorities dealing with eHealth. These technical specifications are laid down in the Guidelines by the eHealth Network on interoperability specifications for cross-border transmission chains between approved Tracing Apps ("eHealth Network Guidelines"), published on 16 June 2020.

The model adopted by the eHealth Network Guidelines is a Federation Gateway Service. The eHealth Network considers this to be the least complex and most robust way to connect the backends behind all the different national Tracing Apps. It accepts diagnostic keys from all EU-member states and provides them for all EU-countries for download. With the Federation Gateway Service, each mobile device communicates with the corresponding national backend. Each national backend uploads the diagnostic keys of its users with confirmed infection every few hours and downloads the diagnosis keys from other member states participating in this system. The Federation Gateway Service synchronizes the diagnostic keys across all national backend servers.

The eHealth Network visualizes the Federation Gateway Service as follows: If an app user in country A receives a positive test result, a diagnostic key is sent to the corresponding national backend of the Tracing App in country A. The diagnostic key is then uploaded to the Federation Gateway Service, downloaded from the backend in country B, and finally downloaded by users in country B who have traveled to country A. However, only those users in country B who have had close contact with the infected person in country A will receive a warning of possible exposure.

Storage of user information

According to the adopted eHealth Network Guidelines, the Federation Gateway Service stores the information of the currently infected users and the countries they have visited, but it does not know the true identity of those users, and it does not know who has come near the infected users. Further, the exchange of data is encrypted so that it is not possible to identify individuals.

The importance of interoperability and common safety standards

The establishment of common eHealth Network Guidelines for the cross-border exchange of information could help in the pan-European fight against the COVID-19 crisis. Of course, the Federation Gateway Service first needs to be set up and the national Tracing Apps need to be established/updated before a cross-border tracing becomes reality. However, the successful cooperation and implementation of the eHealth Network Guidelines in the Member States could also lay the foundation for other future digital health projects on European level. In fact, the EU Commission has already recognized the importance of interoperability between eHealth applications in 2012 in it's so called eHealth Action Plan. According to this plan, the benefits of interoperable eHealth solutions range from improved quality and safety of care through strengthened coordination, up-to-date patient status information and evidence-based clinical guidelines to support decision-making procedures, enhanced safety of treatments received, delivery of care at the point of need, integrated care including quality and safe treatment abroad and, of course, significantly lower implementation and integration costs, opening up competition and reducing costs for developers. The fight against the COVID-19 pandemic could mark an important step towards common standards for interoperability, quality and safety of digital health services in the EU.