NHS Covid-19 App error left thousands unaware they need to isolate

A reported error with the NHS Covid-19 App has left potentially thousands of people unaware they may have been exposed to coronavirus. The contact-tracing app was set at the wrong sensitivity level, meaning many users were not sent self-isolation alerts after they came into contact with infected people. The error meant users whose “risk score” should have triggered an alert were not notified, The Sunday Times first reported. The app, launched a month ago on 24 September, has been downloaded more than 19 million times. It was updated last week to improve accuracy and notifications which was “expected to increase the number of people asked to self-isolate by the app”. Since its launch “shockingly low” numbers of people had been sent warnings about potential exposure to the virus, a government official told The Sunday Times.