The RKI estimates the contribution that the Corona-Warn-App makes to containment to be roughly as high as that of all health authorities together. [1] I'm surp

The RKI estimates the contribution that the Corona-Warn-App makes to containment to be roughly as high as that of all health authorities together. [1] I'm surprised your brother has not received any notifications. My partner is a doctor at a major university hospital and has been warned repeatedly to say the least. During the second wave, the Corona Warn App showed low or high risk warnings pretty much every week. [1] https://www.heise.de/news/RKI-Schaetzung-Warn-App-hat-mehr-als-100-000-Infektionsketten-unterbrochen-6070747.html https://www.heise.de/news/RKI-Schaetzung-Warn-App-hat-mehr-a... (German)