A total of 395,971 alerts were sent to users of the NHS Covid-19 app in England and Wales in the week to July 28 down 43 per cent on the previous week, government figures show.
The alerts are sent to someone if they have been in close contact with someone who had tested positive for coronavirus.
The Government earlier this week announced it was updating the NHS app so fewer contacts would be instructed to isolate.
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, which caused staffing issues across multiple industries.
Health and Social Care Secretary Sajid Javid said the “logic” behind the app was being tweaked, although the sensitivity and risk threshold would remain unchanged.
Instead of checking contacts for five days before a positive test, the app will only go back two days.
It comes as analysis suggested 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 per cent of users obeyed orders to self-isolate.
