610 B

--* A mean number of 4.2 notifications were sent per user who tested positive and accepted contact tracing--

  • As of 6th October 2021, ~6.9 million contact tracing alerts have been sent (from NHS, "Number of contact tracing alerts sent (England)") with ~2.1 million positive tests reported in app (same link, "Number of test results linked to the app (England)", "Total positive test results")
    • Therefore, notifications were sent to, on average, roughly 3 people who came into 'close contact' with a person who tested positive and reported it.