How reliable is the Test and Trace app?
The ‘Great Unlocking’ is hit by surging numbers of people forced to self-isolate – including the PM

As England lifts its remaining social distancing measures today, hundreds of thousands of people are unable to leave their homes in what is being dubbed “pingdemic chaos”.
Even Boris Johnson and Rishi Sunak are spending so-called “Freedom Day” in self-isolation after being in direct contact with Health Secretary Sajid Javid, who has tested positive for coronavirus.
The prime minister and chancellor initially tried to escape their ten days of solitude by taking part in a “test and release” trial, but swiftly changed their minds following an intense backlash yesterday.
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The “Great Unlocking” has “fuelled fears about spiking cases bringing the economy grinding to a halt, as more and more people are doomed to house arrest”, says the Daily Mail.
Supermarket Iceland and brewer Greene King are the latest businesses to report that they have had to shut outlets due to staff being forced to isolate by the NHS Test and Trace app.
Data shows that more than half a million people were “pinged” by the app in the first week of July, a 46% jump on the previous week, and it is expected to rise as cases surge.
Business lobby group the CBI has warned of “crippling staff shortages”, with one in five High Street workers said to be in quarantine.
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It comes after The Telegraph said it had discovered hundreds of people complaining about being “pinged” even though they had not left their homes, with sources close to the app team admitting the Bluetooth signal was “strong enough to penetrate walls”.
“Cases included a carer who had to cancel her father’s cancer appointment after her two neighbours tested positive for Covid,” said the paper.
A government spokesman said the number of these cases was not large enough to be considered “an issue” but did not deny that it could happen.
While we know that “the technology behind the app is far from perfect”, the evidence suggests it is “about as reliable as asking people to remember their close contacts from the previous week”, says Rory Cellan-Jones, technology correspondent for the BBC.
The epidemiologists who advise the government point to a paper in the journal Nature, which shows how the app potentially saved up to 8,000 lives last autumn, he says.
They believe the rising number of pings accurately reflects the surge in new daily cases, which have been reaching around 50,000 for the past few days. “In other words – it is working just as intended,” says Cellan-Jones.
And, as England “limps uncertainly into so-called freedom day”, the programme becomes “arguably even more crucial”, says The Guardian, although there are “troubling questions” around compliance.
Research suggests only a minority of people with Covid symptoms are coming forward for testing and a growing number of people are deleting the app altogether, reports the paper. A Savanta ComRes poll published last week found that only two in five adults currently have the app, and one in five said they used to have it but have since deleted it. This rose to a third among those aged 18 to 34.
“Social media was awash on Sunday with people saying they had ditched it, many blaming Boris Johnson and Rishi Sunak’s initial plan to avoid isolation before their U-turn,” says The Guardian.
Last night, the prime minister acknowledged it was “frustrating” to be pinged, but urged the public to “stick with the programme and take the appropriate course of action when you are asked to do so by NHS Test and Trace”.
But former PM Tony Blair has warned that more people are likely to abandon the app unless the government brings forward its plan to drop self-isolation for people with both vaccines. It “just doesn’t make any sense” to close down large parts of the economy while lifting restrictions at the same time, he told The Sunday Times.
Vaccines Minister Nadhim Zahawi told media outlets this morning that the government would not be altering the sensitivity of the app and that double-jabbed contacts will have to wait until 16 August to avoid self-isolation, as planned.
Amid all this talk of a “pingdemic”, says Stephen Bush in the New Statesman, it is easy to forget that this “isn’t a glitch in the system or some strange oversight”.
It is a “feature, not a bug, of England unlocking”, he says. “Complaining about a pingdemic is a bit like complaining that your fire alarm has gone off because you’ve burnt something on the hob: yes, it’s a pain, but the problem isn’t the fire alarm.”
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