There are many reasons covid-19 contact tracing apps might not work

By Adam Vaughan

Steve Taylor/ SOPA Images/Sipa USA

As countries search for methods to exit lockdown and avoid or handle a 2nd wave of covid-19 cases, numerous have actually turned to the guarantee held by contact tracing apps. In an unusual display of cooperation, Apple and Google recently partnered to help the innovation work successfully.

Such apps look appealing to nations aiming to raise constraints, but there is growing proof that it will be challenging to make them work. A simulation of a city of 1 million people by researchers at the University of Oxford, released yesterday, discovered 80 percent of smart device users in the UK would require to install a contact tracing app in order for it to be effective in reducing an epidemic– that’s 56 per cent of the nationwide population. The UK’s primary clinical advisor, Patrick Vallance, has suggested he believes such apps might have a function to play in contact tracing however that it would be a high order to get 80 percent of smart device users in the UK to use them.

That is a hard target for the UK’s NHSX, the National Health Service digital improvement unit, which is establishing such an app. In Singapore, just an estimated 17 per cent of the population has actually installed a contact tracing app launched last month.

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The principle behind contact-tracing apps is fairly basic. Once set up, they use Bluetooth low-energy (LE) innovation to tape-record when a phone has actually come into close distance with anyone else utilizing the app. In theory, the apps work anonymously and only store information temporarily, without collecting location.

Bluetooth issues

However even if it was in some way feasible to get such high setup rates with voluntary take-up, there is the big concern of whether using Bluetooth to develop a contact works well, said Katina Michael at Arizona State University and Roba Abbas at the University of Wollongong in a joint email to New Researcher “How trusted is the system to gather proximity information? The series of Bluetooth is much bigger than 1.5 meters for social distancing,” states Michael.

Ross Anderson at the University of Cambridge says the range of Bluetooth can differ greatly depending upon how individuals hold their phones, and whether they are indoors or outdoors. He also explains the signals pass through walls, so people behind screens and in different spaces could be needlessly flagged as having had contact. The result might be a flood of incorrect positives. Even the Oxford group, which is encouraging NHSX on its app, state the accuracy with which Bluetooth can be an useful proxy for virus transmission threat is “currently uncertain”.

A further prospective problem is the quality of the information. Abbas and Michael say they understand that many apps being considered would just tape-record contacts at five minute cycles, which may mean infectious contacts are missed out on.

There are a host of other questions. Key are trust in between people and governments, how personal privacy is preserved, keeping the apps voluntary, and how to likewise secure individuals who may not have a smartphone or the capability to install an app– a group that is most likely to consist of numerous vulnerable older people. The American Civil Liberties Union yesterday set out a list of principles, including the need for an exit technique for such apps, to prevent such systems being maintained for “monitoring creep” after an epidemic has passed.

Nonetheless, many countries are on the verge of deploying apps. One of the most high profile existing apps has been Singapore’s TraceTogether app, developed by the city state’s federal government.

Anderson is damning about the potential customers for apps. Vallance thinks apps ought to be part of a much wider contact tracing technique, while the UK health secretary Matt Hancock said today that such apps were a “vital” part of government efforts.

Nevertheless effective the apps turn out to be, they can not be a silver bullet for exiting social distancing measures, and should be part of a much more comprehensive effort of testing and contact tracing.

” Contact tracing apps are likely to be used as a way for fighting the spread of covid-19 They can not be utilized in isolation. The apps themselves will not contain the spread,” states Michael.