The NHS Covid-19 app will be an “important pillar” in controlling the spread of coronavirus as the UK comes out of lockdown.

Wolfgang Emmerich, founder of Zühlke Engineering which helped build the app, said the app has been updated weekly since its launch “as policy and science changes” and will continue to be updated as lockdown restrictions are eased.

“When lockdown ends later in the year, social distancing, vaccines, regular testing and using the app will all be important pillars of controlling the virus’s spread,” he told Digital Health News.

The government announced its roadmap to ease lockdown on 22 February, with schools reopening from 8 March and outside venues, non-essential shops and gyms able to reopen on 12 April provided data suggests it is safe to do so.

Emmerich said the app was a “highly effective” tool to reach people who have come into contact with the virus and need to self-isolate.

“As we come out of lockdown and people want to go to events, restaurants, and social gatherings, we can expect its strong use to continue and probably increase in 2021,” he added.

“We are now working on improvements to the QR codes and venue check-in features that will be required when the hospitality industry reopens in order to improve contact-tracing of people who have visited venues that were linked to infections.”

More successful than expected

Emmerich told Digital Health News the app had been “more successful” than anticipated, but there was still work to be done to encourage people to use the app to control the infection as life goes back to normal.

“Yes, we have 20 million downloads and about 16 million people use it day in, day out, but there is still 40% of the population who could use it but don’t,” he told Digital Health News.

“This is what we have to improve. It needs to be a combination of changes to the app to make it even more attractive to use, but also communication and advertising to let it be known that every 1% of userbase significantly reduces infections.

“That is the biggest lever we have in the short term to make a difference.”

Since the app’s launch in September 2020 it has been downloaded 21.63 million times, with 1.7 million users advised to self-isolate following close contact with someone who had tested positive, Department of Health and Social Care figures show.

Emmerich said it had undergone weekly updates, including the adding of local tier information when tier systems were introduced; interoperability with the Northern Ireland and Scottish app; and the implementation of self-isolation payments.

Changes also needed to be made as new variants of Covid-19 emerged.

“We changed the sensitivity of the exposure notification algorithm and we are going to have to make similar changes if it turns out any other variants that are emerging need an intervention,” Emmerich said.

“As the policy response changes to the pandemic, and as the science changes, we have constantly updated the app and we will continue to do that.”

A tool for prevention

Researchers from the Alan Turing Institute and Oxford University estimate that about 600,000 new cases have been prevented through the use of the app.

Data from the app is now being published weekly alongside NHS Test and Trace data.

But the data does reveal how many people followed advise to self-isolate following a notification, or how many of the alerts were false positives.

Mark Briers of the Turing Institute said: “Using the NHS Covid-19 app is the fastest way to know when you have been at risk of catching the virus and our analysis shows when more people download the app they can have a disproportionately positive impact on driving down case numbers in the community.”

For a more in-depth look at the NHS Covid-19 app, and what went wrong along the way, take a look at our timeline of events here.

The app can be downloaded from the Google Play Store and the Apple App Store. More information can be found on the NHS Covid-19 app website.

We are the hosts of Digital Health Rewired 2021, the must-attend virtual festival celebrating the best of digital health and care, taking place across 15-19 March 2021. Get a flavour of Rewired 2021 from the video below. You can book your place here