Claim: In October, Test and Trace was reducing R by between 0.3 and 0.6.
Fact-check: We don't know how much Test and Trace affects the spread of Covid-19 - Full Fact
Verdict: we don't know this for sure. a small part of the reduction certainly came from test and trace. some of the rest came from people with symptoms self-isolating anyway.
Organisation: Full Fact
Author: Leo Benedictus
Date published: 2021-02-18T00:00:00