SwissCovid: Swiss Corona warning app also works on public transport

Chief Application Developer: “In most cases, it is not necessary to disable SwissCovid”

In a detailed Watson interview, SwissCovid lead developer Mathias Wellig discusses the burning questions and reveals how the Swiss Corona warning app will be further improved.

Mr. Wellig, until recently, the SwissCovid app still had the slogan “Together … Preventing a second wave”. How do you judge that?
Mathias Wellig: We knew that in the event of a second wave like the one we have today, this text would no longer be appropriate. But since we wanted to point out the urgency, we decided to use this wording anyway. With the current version of the application, we have adapted the text to a more general “prevent infections”.

With the latest SwissCovid update, there are several improvements, based on the description, the app should now display notifications (about potential Covid contacts) faster. What does that mean exactly?
With the latest update, SwissCovid is based on the new version 2 of the Apple-Google interface (GAEN API). In the first version there was a limitation that the application could only make the comparison with the published keys twice a day. Now we can do this every four hours. This helps to display warnings more quickly.

What do the innovations in the Apple-Google interface mean for the SwissCovid app?
Now we not only get aggregated values ​​from Bluetooth beacons received in advance, but we also have direct access to more raw data that we can evaluate ourselves. In the current version of SwissCovid, we still rely on the same aggregation that has proven itself in recent months. However, the groundwork has now been laid for us to make improvements. Researchers at EPFL and ETH Zurich are currently looking for such optimizations.

What practical conclusions do you have about the reliability of the application in public transport situations, that is, when you travel by train, bus or tram?
Scientific findings from experiments carried out by EPFL and ETH Zurich show that Bluetooth-based proximity tracking also works in public transport situations.

An Irish study on Bluetooth proximity tracking on trams caused some confusion here. For example, this study assumed a static environment: devices / people would not move. Furthermore, the study authors completely ruled out the necessary calibration of different smartphones.

How good is Google’s calibration of the many Android smartphone models?
The specialists are constantly on the move. The current status of the Google calibration can be seen here on the web.

Hand on Heart: Does SwissCovid Work Reliably?
In the four months that the app is now productive, we’ve only heard isolated instances where SwissCovid users have clearly been misreported.

The answer is positive, we now know from various studies and also directly from the SwissCovid hotline that the Bluetooth-based approach works. But it is also clear that proximity measurements via Bluetooth are not perfect. We have to live with a certain confusion. This is no different with classic contact tracing and also with the transmission of the virus.

SwissCovid has almost 1.9 million active users, Twint reportedly over 3 million. What goes through your head with these numbers?
It shows me that there is obviously the potential for more active users. We must continue to work on this at all levels.

What are the next planned enhancements to the SwissCovid app?
With the second wave, a bottleneck in the SwissCovid application came to light: the creation of Covid codes. We have been looking for solutions here for some time. Starting this week, treating doctors and hospitals can also register to issue Covid codes. As of noon today (November 5, 2020) more than 600 doctors have already registered. We expect to see a clearly positive trend in Covid codes in the coming days.

There are users who, for very different reasons, regularly deactivate the SwissCovid application.
Yes. And sadly, reactivation is sometimes forgotten. Here we would like to point out that in most cases it is not necessary to deactivate the application. For example, if you have been in a protected environment, you will know if you report it to the hotline and will be able to react accordingly. Battery consumption is also often overestimated, usually a few percentage points per day.

And what many do not know either: if you deactivate the application, it cannot sound alarms during this time. For most users, it makes sense to simply keep the application active at all times. But because there are good reasons to temporarily deactivate the application, in the future we will offer the option to set a reminder to reactivate the application immediately after deactivation.

As an added feature, we have considered the options to show where you can test directly from the app. This is initially implemented as a simple forwarding, as the data exists in different forms at the cantonal level.

Delays in issuing Covid codes were identified as one of the biggest issues with the SwissCovid system. Doctors can now also issue the codes. From the point of view of the application development manager, are there other ways to improve efficiency?
We hope that the problem will be alleviated for the first time when there are more and more doctors “on board” for the Covidcode exhibition. But we are always thinking of new approaches so that we never run into a bottleneck again.

What kinds of approaches are these?
There are no out-of-the-box approaches yet. We basically look for optimizations throughout the entire process.