Last reviewed 3 August 2021

Amid reports that people were deleting the app to avoid being notified to self-isolate, the Department of Health and Social Care (DHSC) has announced that changes have been made so that fewer contacts will be advised to self-isolate following a close contact with a positive case.

As part of a review into the app, the logic which underpins how close contacts are notified was updated on 2 August.

Previously, for people who input a positive test but are asymptomatic, the app looks for close contacts five days prior to that positive test. This has been updated, based on public health advice, to look back at contacts two days prior to the test.

Health Secretary Sajid Javid said: “We want to reduce the disruption that self-isolation can cause for people and businesses, while ensuring we’re protecting those most at risk from this virus. This update to the app will help ensure that we are striking the right balance”.

The change will mean fewer contacts that took place when the positive case was unlikely to be at the peak of their infectiousness are advised to self-isolate, he explained, reducing the overall number of notifications sent by the app.

The DHSC insists that the update does not impact the sensitivity of the app, or change the risk threshold, and will result in the same number of high-risk contacts being advised to self-isolate.

It highlights new analysis which shows that, in the first three weeks of July as cases were exponentially rising, the app averted up to 2000 cases per day. Assuming 60% compliance with instructions to self-isolate, this meant that it prevented over 50,000 further cases of Covid-19 when chains of transmission are taken into account. This is estimated to have prevented 1600 hospitalisations.

Dr Jenny Harries, CEO of UK Health Security Agency, said: “The app is the simplest, easiest, and fastest way to find out whether you have been exposed to the virus, and it has saved thousands of lives over the course of this pandemic. I strongly encourage everyone, even those fully vaccinated, to continue using the app”.