This dataset covers pupils in state-funded schools only (including special schools and sixth forms attached to schools). Therefore, the data will differ from the administrative data on COVID-19 cases published by the UK Health Security Agency and our estimates of infection from the Coronavirus Infection Survey (CIS).

This is analysis of new and recently collected data, and our understanding of their quality will improve over time. The estimates presented in this release are Experimental Statistics as the NHS Test and Trace data are subject to further quality assurance tests.

At each time point recorded in this dataset different variants of SARS-CoV-2 were dominant in the UK.

Using Test and Trace data to monitor trends in coronavirus (COVID-19) infection relies on infections being recognised and a willingness to test if symptoms are identified. Changes to isolation rules over time may also influence the willingness to test and the impact of these rules and any changes could vary between different socio-demographic groups.

This dataset includes reported lateral flow device (LFD) test results. Access to free LFTs for everyone in England was introduced between the two time periods being compared (on 9 April 2021), with the aim of uncovering asymptomatic cases. At the beginning of the 2021 to 2022 autumn term, secondary pupils were advised to take two on-site LFD tests prior to their return to school and then continue testing twice weekly at home. Variation in the uptake and/or reporting of LFD testing could also impact on the trends reported here.