Contact tracing revisited: whatever happened to the UK’s smartphone app?

This blog was originally published in Business Matters magazine on the 23rd June 2020.

In my column on 4 May in Business Matters magazine, I reported that the UK government was trialling a contact tracing app, which was due to be rolled out nationwide later that month. But it never happened. And last week, the government announced that it was abandoning the app, to be replaced at some unspecified time in the future by a new version based on technology developed jointly by Apple and Google. So what went wrong? Will we ever see an effective contact tracing app widely used in the UK?

It’s fair to say that the benefits of a contact tracing app were always oversold. Think back to earlier this spring when the coronavirus pandemic was at its height, we were all adapting to lockdown, and the news was full of terrible statistics of rising deaths and infections. Everyone, not just the government, was desperate to find solutions. In the absence of a vaccine, the idea of a neat technological solution that could ease the lockdown was just too good to ignore. The government put the proposed smartphone app at the very heart of its planned track and trace strategy.

Despite the fanfare, concerns were raised about the government’s approach from the start. I asked in my column why the government had chosen to use a centralised model for its proposed app, rather than the decentralised approach which underpinned the Apple and Google technology and had already been adopted in other European countries. Broadly, the centralised model involves creating a central database of contacts, whereas, in the decentralised model, contacts are stored locally on individuals’ own phones and only shared when an infection is confirmed. Centralised databases raise privacy and security concerns, and legitimate questions were asked about what the government may do with the data collected. Reassurances that any data collected would only be used for contact tracing and the fight against coronavirus did not convince everyone. Even the influential Parliamentary Joint Committee on Human Rights arguing for a new law to protect against potential ‘mission creep’, as well as outlawing discrimination against those who chose not to install or use the app. The government rejected this proposal as unnecessary.

As the number of cases of coronavirus continued to fall, so the chances of coming into contact with someone infected also fell. The government was going to need a large percentage of the population to download and use its app for it to succeed in making a meaningful difference. It was reported that as many as 80% of smartphone users would need to be running the app. But with ongoing concerns about privacy, this was already a challenge. The issue of trust then became a real problem for the government in the wake of the Dominic Cummings saga, which broke in late May. Regardless of the rights or wrongs of that particular scandal, the opinion polls showed it resulted in a significant fall in trust in the government. This has been backed up by recent polling which has shown only a minority of people would be willing to install the government’s own app.

While the UK government continued to pursue a centralised option, other countries were moving in the opposite direction. Most other European countries, with the notable exception of France, had chosen to work with the Apple and Google technology to create their own apps based on the decentralised model. It was becoming an international standard. Questions were raised about interoperability and when international travel resumes, whether the UK app will work with other countries’ own apps. This is especially important in Ireland, which is developing its own decentralised app. Meanwhile, Germany’s decentralised app was launched on 14 June and has already been downloaded 10 million times.

In the end, it was the practical issues which finally doomed the UK’s app in its current form. As well as working with Google to develop its own technology to assist contact tracing, Apple had put in place restrictions on the use of Bluetooth for the sort of centralised tracing envisaged by the UK government. So, the government’s own app simply did not work properly on iPhones, which represent a significant share of the UK smartphone market. The government was warned of this as long ago as April but had hoped to find a technical solution. Clearly, that has not been possible.

The recent government u-turn means that there is now no firm timetable for an app to be launched, and there must now be a question mark about whether an app will ever be launched in the UK which can help with contact tracing. But this isn’t just a story of government mistakes. There remain real technological difficulties, even with the Apple and Google model. Bluetooth signals are not intended to measure distance accurately, and so an app could give a high rate of false positives or miss some close contacts altogether. There are no easy answers to these technical questions. This is still an unproven technology.

Finally, there is the issue of need. A smartphone app is undoubtedly more ‘sexy’ (and headline-grabbing) than plain old manual contact tracing. But the more we learn about the virus, the more we have realised that manual tracing was always going to be key. The virus is mainly spread when you spend longer periods of time indoors with others, such as at home or in the workplace, rather than via one-off chance encounters on the street. So if you are infected, you are likely to know nearly all of your ‘contacts’ personally. The main risk of spreading via an unknown contact is on public transport, the use of which has fallen dramatically and where the wearing of masks is now compulsory. It may be that we didn’t need an app all along.