Nationwide restrictions came into force in England on 5 November. A typical new infection takes in the region of five days to produce symptoms and time is then required for them to request and take a test, and for the results to be processed. There is a further delay before changes in infection numbers become apparent in hospitalisation and death statistics. It is therefore too early to measure the impact of the new restrictions on COVID-19 levels in England, as current data will be reflective of infections occurring before those restrictions came into force.
The Joint Biosecurity Centre is developing methodology to measure the effectiveness of these restrictions once sufficient time has elapsed for any impact to be apparent in data sources.