Coronavirus: NHS contact-tracing app is tested at RAF base

The NHS is testing its forthcoming Covid-19 contact-tracing app at a Royal Air Force base in North Yorkshire.

It works by using Bluetooth signals to log when smartphone owners are close to each other - so if someone develops Covid-19 symptoms, an alert can be sent to other users they may have infected.

In its current state, it tells users either: "You're OK now," or: "You need to isolate yourself and stay at home."

The health secretary for England said the trials "are going well".

"The more people who sign up for this new app when it goes live, the better informed our response will be and the better we can therefore protect the NHS," Matt Hancock told the House of Commons.

He added the software would be used in conjunction with medical tests and manual contact tracing by humans.

But some experts say the government may be putting too much faith in technology.

"We don't need fancy expensive apps where people are going to be exposed to issues of data privacy," Newcastle University Centre for Excellence in Regulatory Science director Prof Allyson Pollock told BBC News.

But some experts say the government may be putting too much faith in technology.

"We don't need fancy expensive apps where people are going to be exposed to issues of data privacy," Newcastle University Centre for Excellence in Regulatory Science director Prof Allyson Pollock told BBC News.

"We should be following... a low-tech model, using people and telephone [interviews].

"Clinical observation, we found in China and Singapore and Korea, is actually more efficient and gives many more positives."

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The NHS hopes to release the app by mid-May, although a final decision on timing will be taken by the government.

Shopping simulation
RAF Leeming was chosen to host the trial of an early "alpha" version of the software because it has past experience of testing apps and other new processes on behalf of the military.

It set up a scenario designed to simulate people's experience of going shopping, using Bluetooth LE (low energy) signals to log when two phones were near to each other.