The CoronaMelder app has not been able to do much in the fight against the corona virus so far.

In the six months since the app has been in use, the Netherlands has largely been in lockdown: a phase in which its usefulness is declining.

Committed and independent scientists expect that the corona app can only really show its added value once society partially reopens.

While tens of thousands of infected people are found every week through regular testing, a total of 11,154 people tested positive after a CoronaMelder warning.

That's 1.2 percent of the nearly 915,000 positive tests since the app went live.

With the app, an infected person can anonymously warn other app users who have been in the area for at least 15 minutes in the past few days.

People in the cinema, public transport or in the shop can then receive such a signal, while they are normally not in the picture during the contact investigation of the GGD.

But encounters between people who don't know each other take place less during a lockdown.

Buildings where people who do not know each other come together are largely closed.

While CoronaMelder can show its added value precisely there.

Measures since CoronaMelder has been active:

  • October 10, 2020

    CoronaMelder is taken into use nationwide.

    Anyone who receives a warning must be quarantined for ten days.

    Testing is only possible if you also have complaints.

  • October 14, 2020

    The Netherlands goes into partial lockdown for the second time.

    Restaurants and cafes must close and unnecessary shops must close from 8 p.m.

  • November 3, 2020

    Publicly accessible buildings will be closed.

    Theaters, cinemas and museums will close for two weeks.

  • December 1, 2020

    From now on you can request a test after a CoronaMelder warning if you do not (yet) have any complaints despite the report.

    In this way, infected people can be found without symptoms.

  • December 15, 2020

    The Netherlands will be subject to a strict lockdown.

    Cinemas, casinos, museums and many other places where people can bump into each other have to be closed again.

    Gyms and non-essential stores must also close their doors.

  • 23 January 2021

    The curfew starts: people are in principle no longer allowed to stay on the street between 9 p.m. and 4.30 a.m.

    From March 31, the start time is 10 p.m.

"People should meet much less others during a lockdown," says Wolfgang Ebbers.

He is conducting research into the contribution of the corona app on behalf of the Ministry of Health.

"In theory, the app adds less during a lockdown."

Is the CoronaMelder a drop in the ocean during lockdown?

Ebbers can agree with those words, as long as it does not suggest that the app is not contributing.

"I once said to the ministry: be glad that there aren't so many tests being done as a result of a report in the lockdown. If the numbers were higher, it means that people are not following the rules."

Corona tests per week since June 2020

The graph runs until March 28, 2021 (week 12), because more recent CoronaMelder figures can still be corrected.

Due to retrospective corrections, the figures also differ slightly from data reported by in previous articles.

"The effect of these kinds of apps is less if you constantly see the same people, such as through a lockdown or curfew," says Frank Dignum of the University of Umea in Sweden.

He used simulations to research the usefulness of these types of corona apps.

The figures for the past six months come as no surprise to him.

"These kinds of apps are the most profitable when you see a lot of people you don't meet otherwise," he says.

The app warned 2,625 infected people without complaints

Since December, a warning from the CoronaMelder has been enough to get you tested.

Of the 8,049 positive tests that were determined after a report, 2,625 infected people had no complaints at the time of testing.

That is one in three.

That is where the strength of CoronaMelder lies, says the ministry.

Without the app, these people would have been found later or not at all.

It is a number that says something concrete about the promise of the app: detect infected contacts as quickly as possible.

Yet those 2,625 people cannot be put away as a net result, Dignum notes.

"Some of them will probably be housemates. You would have found them without an app anyway."

It is unclear how large that group is.

The ministry does not keep statistics as to whether people who have themselves tested because of a CoronaMelder warning also have an infected roommate, a spokesman said.

CoronaMelder may add more after lockdown

Ebbers and Dignum think the app will add more as soon as the Netherlands leaves the current lockdown.

"People then get more freedom, while the virus is still circulating," says Dignum.

"We expect that more infections will take place outside your immediate social circle," says Ebbers.

"The contribution of CoronaMelder could therefore be greater when society opens up again."

He emphasizes that people must also adhere to the advice to make the CoronaMelder useful.

Recent research by Ebbers showed that more than half of CoronaMelder users do not go into quarantine after a warning.

"The cabinet should also try to find ways to get people who want to take more freedoms to download CoronaMelder," said Dignum. "If people go to the park en masse in good weather, but no one has that app, it won't be of much use yet."