The Prime Minister, Boris Johnson, has doubled down on claims that no country has an effective smartphone app that can track and trace cases of Covid-19 infection.

Mr Johnson came under pressure from Labour leader, Sir Keir Starmer, over the government’s decision to scrap an NHS app weeks before it was expected to be rolled out across the country.

Lord Bethell, the minister overseeing the development of the NHSX app, told MPs last week that the app may not be ready before the winter, saying: “It isn’t a priority for us at the moment.”

At Prime Minister’s Questions today, Mr Johnson told Sir Keir: “I wonder whether the right hon. and learned Gentleman can name a single country in the world that has a functional contract tracing app—there isn’t one.”

He made an almost identical remark earlier this week, telling parliament: “No country currently has a functioning track and trace app.” Is this true?

Dozens of countries have apps

It’s plainly the case that many countries have in fact already launched apps that aim to track physical contact between users and alert people to the possibility that they have been exposed to the novel coronavirus.

The US magazine MIT Technology Review lists more than 20 apps backed by national governments that have already gone live.

Singapore launched its application as early as March. Australia’s app was available for download on April 26.

Different systems

It’s immediately obvious from this database that countries have gone down very different routes in trying to come up with a design that works.

Broadly speaking, some countries have chosen to use GPS data to track people’s location, while most use Bluetooth to detect other phones in the area that are using the app.

Many countries have chosen to use a platform developed jointly by Google and Apple to enhance Bluetooth connectivity on Apple and Android devices.

Britain’s NHSX wanted to develop an app that would work independently of the joint solution offered by Google and Apple, before changing its mind.

The original plan for a bespoke app would have allowed a “centralised” design – where data from phones could be pooled and made available to the NHS.

Apps that use the Google/Apple technology are “decentralised”, which means data stays on individual devices, helping to safeguard privacy.

France has pushed on with an app that does not depend on technology from the two tech giants, while Italy, Germany and Switzerland have launched apps that use the Google/Apple system.

So some countries have done what Britain originally intended to do, and others made the decision much earlier to go down the road that the UK government now favours.

Do any of the existing apps work well?

This appears to be the argument Mr Johnson is making when he talks about no “functioning” apps: the apps may exist, but they are not up to the job.

Downing Street offered a clarification of his remarks today, with his official spokesman saying the various apps that are in existence around the world “did not fully record people’s contacts and that they were not reliable enough to be used to tell people to self-isolate”.

It’s fair to say that almost every major national effort to create an app has faced some criticism over technical or ethical issues.

Singapore’s TraceTogether – the first major Bluetooth-based app – was judged to be of limited effectiveness by academics in one early study.

Officials in charge of tracing in Iceland gave the country’s GPS-based app a lukewarm reception in May.

Many countries have reported lower-than-expected uptake, which dilutes the effectiveness of tracing apps.

Ultimately, there’s no international agreement about what success or failure looks like, and there is no consistent reporting of results across countries, making it hard to determine whether an app is working adequately.

Even if we do get good data on how the apps are working, we would arguably need to hold large randomized controlled trials to see if the effect or apps are clinically significant.


Having said all that, some experts point to Germany as an example of a country that has launched a Bluetooth/Apple-Google-based app with promising early results.

According to the Robert Koch Institute – Germany’s national agency for the control and prevention of diseases – the Corona Warn-App had been downloaded 12.6 million times as of today. That’s nearly a fifth of all adults in Germany.

It isn’t clear yet whether the app has had any significant effect on reducing coronavirus transmission. But we don’t know what information the British government is relying on if it considers the German app to be a failure.

We asked Downing Street what evidence they had on the effectiveness of apps internationally, and we were simply referred to the words of the Prime Minister’s spokesman, quoted above.

Dr Michael Veale, Lecturer in Digital Rights and Regulation at UCL, who helped develop the DP-3T tracing system, told FactCheck: “The UK government has not published any information on why it considers the German Corona Warn App not to function. The UK government was also planning for an app where quarantine instructions for others would be based on self-reported symptoms, which anyone could have faked, and so this concern for reliability appears to be very new.

“Insofar as no country has deployed an app for long enough to properly evaluate how important it is in fighting the pandemic, the Prime Minister would be correct; however the only way to find this out would be to build, publish and study a functioning app.”