The adoption of contact tracing applications of COVID-19 by European governments

Figures & data

Table 1. Digital contact tracing application specifications.

Specifications	Potential options
Proximity measurement mechanisms	Bluetooth Local GPS
Data storage	Centralized storage (data is automatically stored on a central server) Partially centralized (only data from infected individuals is transferred to a central server) Decentralized (data is stored solely on smartphones)
Data collected	Information exclusively related to interactions (e.g. location, duration, date, numerical key) Ability to encode demographic and medical data (age, gender, diseases, medications, etc.)
Notification mode	Binary notification (information on whether or not the user has been exposed to an infected individual) Graduated notification (information regarding the potential level of risk to which the user is exposed based on his/her interactions)
Method of installation	Manual installation (the user takes care of installing the application) Default installation (installation is automatically carried out by the manufacturer)
AI module	Integration of an AI module to measure the level of risk to which a user may have been exposed Exclusion of an AI module to measure the level of risk to which a user may have been exposed
Relationship with regards to manual tracing	Application is used in conjunction with manual tracing Alternative to manual tracing

Table 2. Studied digital contact tracing application specifications.

Specifications	Coronalert	NHS Covid-19	StopCovid
Proximity measurement mechanisms	Bluetooth	Bluetooth	Bluetooth
Data storage	Decentralized	Decentralized	Centralized
Data collected	Information exclusively related to interactions	Information related to interactions and postcode	Information exclusively related to interactions
Notification mode	Binary notification	Binary notification	Binary notification
Method of installation	Manual installation	Manual installation	Manual installation
AI module	Not used to compute the risk level	Use to compute the risk level based on the user’s address	Not used to compute the risk level
Relationship with regards to manual tracing	Use with manual tracing	Use with manual tracing	Use with manual tracing

Table 3. Issues concerning the adoption of the exposure notification and contact tracing app.

Issue	StopCovid	NHS Covid-19	Coronalert
App Functioning	Bluetooth activation and proximity measure.	Bluetooth Activation and proximity measure, prior to the iPhone 7 is not compatible with NHS Covid-19.	Adaptation of an application developed in another European State.
Security and Data Protection	Opposition to centralized data storage, collection of private data, and risks of piracy.	Opposition to centralized data storage.	Collection of 13 different pieces of private data, no guarantee of de-anonymization, and low protection of the Sciensano database.
Effectiveness	Detection rate (between 75% and 80%) and utilization rate (3.6 % of the population).	Detection rate (31% of risky cases were missing and 45% were misidentified as risky) and utilization rate (22.5 % of the population).	Utilization rate (15 % of the population).
Relevance	23% of French citizens do not own smartphones.	21% of British adults do not own smartphones.	22 % of Belgian citizens do not own smartphones.
Acceptability	45% of French citizens are ready to use the app.	–	–
Time	Several postponements of the launch date.	Postponement of the launch date from June to September.	–
Interoperability	Absence of interoperability between the French app and the European ones.	–	–
Political Power	–	–	Institutionalized collaboration between regional and federal levels.