In May 2020, when the pandemic was still fresh and models were trying to better understand what was to come, one could still dream.
"Using a contact-tracing app would be enough to stop the epidemic if enough people used it," Oxford University scientists wrote in Science at the time, and for a brief time it was thought that would certainly be true.
It sounded so logical: Of course, a pandemic in the 21st century would have to be very different from the Spanish flu.
Everyone would be informed about risks in real time and be able to rely on all relevant epidemiological information being collected and used quickly and transparently nationwide.
Today we are smarter, know about the German reality of fax machines and chronic staff shortages in the health system and at the same time have been reminded that a lot of mischief can be done with the digital transfer of personal data to supposedly well-meaning companies.
But have technologically more advanced countries really fared better?
It's not all that clear.
That's what scientists around Eric Topol and Jay Pandit from the American Scripps Research say in an overview article in "Nature Biotechnology".
In it, they pursue the question of what could be learned from more than two years of pandemic about the digital attempts at epidemiological data collection, screening and contact tracing.
The answer: not much.
There are hardly any systematic evaluations.
A rare exception can be found in the United Kingdom.
There it was determined for the end of 2020 that within 13 weeks up to almost one million infections were prevented by using the app.
We do not know whether the same applies to the RKI's Corona warning app.
After all, it was downloaded 45 million times.
She continues to tirelessly send out her warnings.
However, many people have given up trying to really understand how the app works after numerous modifications to the warning algorithm.
Like answering the question of what to do with a red warning — apart from generally being happy that you’re obviously not the only one who still uses the app and dreams of its usefulness.