The NHS Covid-19 app is being updated so fewer contacts will be instructed to isolate after an increase in people being pinged since lockdown restrictions ended.
Instead of checking contacts for five days before a positive test, the app will only go back two days, though the sensitivity and risk threshold will remain unchanged.
Previously, the NHS Covid-19 app would “ping” users if they came into contact with a person with coronavirus in the five days leading up to them receiving a positive test.
The app will now be tweaked to only check for contacts in the previous two days before a positive test, with The Department of Health and Social Care (DHSC) saying this will reduce contacts from when an asymptomatic person was unlikely to be at the peak of infectiousness, and so cut down the overall number of pings.
The move comes as analysis shows that in the first three weeks of July the app could have averted up to 2,000 cases per day, and more than 50,000 cases of Covid-19, including chains of transmission, assuming that 60% of users obeyed the instruction to isolate.
Scientists believe this may have amounted to avoiding 1,600 hospital admissions.
Dr Jenny Harries, chief executive of the UK Health Security Agency has encouraged people to continue using the app, which she called “the simplest, easiest and fastest way to find out whether you have been exposed to the virus”.
A DHSC spokesperson 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,” Mr Javid said.
“This update to the app will help ensure that we are striking the right balance.
“It’s so important that people isolate when asked to do so in order to stop the spread of the virus and protect their communities.”
The large amount of self-isolation instructions sent to users of the NHS Covid-19 app in recent weeks has been dubbed the “pingdemic”.
Almost 700,000 alerts were sent by the app to users in England and Wales for the week to July 21, a record since it was launched.
The large number of pings has caused staffing shortages across multiple industries, including hospitality and retail.
Additional reporting by PA.