- Main points
- Overview of data and methods
- Coronavirus (COVID-19) cases by age and symptoms at time of positive test
- Coronavirus (COVID-19) cases by pupil characteristics
- Positive coronavirus (COVID-19) cases by deprivation measures
- Positive coronavirus (COVID-19) cases by region
- Logistic regression for factors associated with a positive coronavirus (COVID-19) case
- Positive coronavirus (COVID-19) cases by vaccination status in pupils aged 12 to 15 years
- Rate of positive coronavirus (COVID-19) cases by vaccination status
- Coronavirus cases at school level
- Coronavirus cases in school pupils data
- Data sources and quality
- Future developments
- Related links
1. Main points
White British secondary pupils had the largest proportion of their population reporting a positive coronavirus (COVID-19) test in the autumn 2021 term (24.9%); this differs from the autumn 2020 term, when secondary pupils from the Indian ethnic group had the largest proportion of their population reporting a positive COVID-19 test (11.3%).
White British primary pupils had the largest proportion of their population reporting a positive COVID-19 test in the autumn 2021 term (16.6%); this differs from the autumn 2020 term, when primary pupils from the Pakistani ethnic group had the largest proportion of their population reporting a positive test (2.5%).
In the most deprived areas, 9.4% of primary pupils and 15.3% of secondary pupils reported a positive test in the autumn 2021 term, compared with 20.1% of primary pupils and 27.9% of secondary pupils in the least deprived areas; in the autumn 2020 term, the difference between pupils in the most and least deprived areas was smaller.
Pupils with a positive COVID-19 test were less likely to report having COVID-19 symptoms at the time of their positive test in the autumn 2021 term (50.4% of primary pupils and 52.3% of secondary pupils); this differs from the autumn 2020 term (74.3% and 69.3%, respectively).
In the first half of the autumn 2021 term (20 September to 3 November 2021), the rate of pupils aged 12 to 15 years vaccinated with one dose (at least 14 days after vaccination) reporting a positive COVID-19 test was estimated to be 38% lower than unvaccinated pupils.
In the second half of the autumn 2021 term (4 November to 17 December), the rate of pupils aged 12 to 15 years vaccinated with one dose (at least 14 days after vaccination) reporting a positive test was estimated to be 23% lower than unvaccinated pupils.
2. Overview of data and methods
The coronavirus (COVID-19) case data presented in this article are produced using the England school census (ESC) and NHS Test and Trace. It covers pupils in state-funded schools only (including special schools and sixth forms attached to schools). Therefore, the data differs from the UK Health Security Agency's data and insights on coronavirus and estimates of infection in our Coronavirus Infection Survey statistical bulletins.
Using Test and Trace data to monitor trends in COVID-19 infection relies on infections being diagnosed. This is influenced by whether people have symptoms, are aware they may have been in contact with someone infected, and are willing to test. Changes to testing and isolation rules over time may also influence the willingness to test. The impact of these rules and any changes could also vary between different sociodemographic groups.
The data also includes reported lateral flow device (LFD) test results. Access to free LFD tests for everyone in England was introduced between the two time periods being compared (on 9 April 2021), with the aim of identifying and isolating asymptomatic cases to prevent onward transmission.
At the beginning of the 2021 autumn term, secondary pupils were advised to take two onsite 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 affect the trends reported here.
Therefore, when comparing the proportions of pupils reporting positive tests between groups and across time, these figures cannot be used to estimate the true positivity rates among their populations.
This is analysis of newly collected data, and our understanding of it and its quality will improve over time. The estimates presented in this release are Experimental Statistics because the NHS Test and Trace data is subject to further quality assurance tests.
This publication focuses on the autumn 2020 term (1 September 2020 to 23 December 2020) and the autumn 2021 term (31 August 2021 to 22 December 2021) to understand how the characteristics of pupils testing positive changed over time. Data for the spring and summer 2021 terms are also available in the accompanying dataset. At each time, different SARS-CoV-2 variants were dominant in the UK (see Glossary section).Nôl i'r tabl cynnwys
Age and year groups
Ages in this publication refer to the age of the pupil on 31 August at the start of the relevant academic year (31 August 2020 for 2020 to 2021 and 31 August 2021 for 2021 to 2022). Therefore, all pupils in school year reception are recorded as being age 4 years, pupils in school year 7 are recorded as being age 11 years, and pupils in school year 11 are recorded as being age 15 years. Consequently, a pupil's recorded age may not be their actual age at the time of their reported positive test.
A confidence interval gives an indication of the degree of uncertainty of an estimate, showing the precision of a sample estimate. The 95% confidence intervals are calculated so that if we repeated the study many times, the true unknown value would lie between the lower and upper confidence limits 95% of the time. A wider interval indicates more uncertainty in the estimate. Overlapping confidence intervals indicate that there may not be a true difference between two estimates.
For more information, see our methodology page on statistical uncertainty.
Free school meals (FSM)
Free school meals (FSM) are a statutory benefit available to school aged children from families who meet the qualifying criteria published by the Department for Education (predominantly based around income). In this article, we define FSM as pupils having been eligible for FSM in the last six years, using information recorded by schools as part of the England school census.
Rate of pupils reporting a positive test per 10,000 participant days at risk
The rate of pupils reporting a positive test per 10,000 participant days at risk allows us to understand the rate of infection depending on how long participants have been "at risk" of infection. This accounts for participants having been vaccinated at different timepoints. It also accounts for individuals having different durations of time until a positive test.
The figure is calculated by dividing the reported number of positive tests identified by the total number of participant days from the first time a participant became at risk (in either the vaccinated or unvaccinated categories) to their latest reported positive test, or the end of the follow up period. Pupils could switch between unvaccinated and vaccinated after vaccination.
An odds ratio indicates the likelihood of pupils having reported a positive test for coronavirus (COVID-19) given a particular characteristic or variable, compared with a baseline category.
When a characteristic or variable has an odds ratio of one, this means there is neither an increase nor a decrease in the odds of having tested positive for COVID-19 compared with the baseline category. An odds ratio greater than one indicates an increased likelihood of having reported a positive test for COVID-19 compared with the baseline category. An odds ratio less than one indicates a decreased likelihood of having reported a positive test for COVID-19 compared with the baseline category.
People can record several positive tests on the system. Within our figures presented here, we consider positives more than 120 days after the first positive of that infection episode to be new infections, in order to be consistent with our existing publications on COVID-19. This definition will be reviewed in future analysis, following the emergence of the Omicron variant.
Income Deprivation Affecting Children Index (IDACI)
The Income Deprivation Affecting Children Index (IDACI) is used to calculate deprivation deciles based on the proportion of children aged 0 to 15 years living in deprived income households. These are households not working or working on low incomes eligible for means tested benefits.
The index ranks 32,844 Lower Layer Super Output Areas (LSOAs) in England from most deprived to least deprived and divides them into 10 equal groups. For example, small area X is ranked 5,000 out of 32,844 small areas in England, where 1 is the most deprived. This means that small area X is among the 20% most deprived small areas in the country and therefore would be in IDACI decile 2. The Department for Communities and Local Government have published further information.
Variants of Coronavirus
In the time periods analysed in this article, there have been different dominant variants of SARS-CoV-2, the virus causing COVID-19, at each point in time. In the autumn 2020 term, the original strain of COVID-19 was dominant. Alpha then emerged towards the end of the term and became dominant on 21 December 2020. In the autumn 2021 term, Delta was the dominant variant. Omicron infections were identified towards the end of this term but were not considered dominant until 20 December 2021.Nôl i'r tabl cynnwys
13. Data sources and quality
Measuring the data
Data from the England schools census (ESC), NHS Test and Trace (pillars 1 and 2), and the National Immunisation Management Dataset (NIMS) were linked to produce the analysis used in this article. For further information on the data linkage process, please see our Coronavirus (COVID-19) vaccination uptake in school pupils, England: up to 9 January 2022 article.
The ESC is a mandatory annual return to the Department for Education by state-funded schools on a set date. For data in this article, this was 21 January 2021. All pupils attending state-funded primary schools, secondary schools (including sixth forms attached to schools), nurseries, and special schools in England are recorded. This is over 6.9 million pupils aged 12 to 15 years, and approximately 92% of all those aged 4 to 15 years in England.
The Department for Education releases ESC data on schools, pupils and characteristics. All demographic, geographic and personal data used in this article comes from the ESC.
Test and Trace records all coronavirus testing that takes place in England. These figures are updated daily and retrospective updates can be made. The extract used contains data up to 31 December 2021, and the outcome measure includes individuals receiving a positive polymerase chain reaction (PCR) or lateral flow device (LFD) test result recorded in the Test and Trace data.
The NIMS records England's COVID-19 vaccinations programme.
One strength of the dataset is its size. ESC contains pupil level data collected from all state-funded schools in England. This represents over 8 million pupils aged 4 to 17 years and allows for potential analysis of smaller under-representative groups.
The data contains a rich source of background characteristics, which allow us to analyse how the proportion of pupils reporting positive tests for coronavirus differ by sociodemographic group, and examine the extent to which these differences are driven by other factors.
Making use of already existing administrative data sources avoids the need to set up bespoke surveys, which can be costly and suffer from response bias.
Using Test and Trace data to monitor trends in COVID-19 infection relies on infections being diagnosed. This is influenced by whether people have symptoms, are aware they may have been a contact of someone infected, and are willing to test. 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 sociodemographic groups. This means the Test and Trace data cannot be used to provide an estimate of the true positivity rates within the population.
Access to free LFD testing for everyone in England was introduced between the two time periods being compared (on 9 April 2021), with the aim of uncovering asymptomatic cases. Variation in the uptake and/or reporting of LFD testing could also affect the trends reported here.
The latest available ESC data relates to the previous academic year, so pupils may not be recorded in the schools they currently attend. Therefore, school level analysis of secondary schools for 2020 to 2021 relates to those aged 11 to 15 years. For 2021 to 2022, school level analysis relates only to those aged 11 to 14 years (those now aged 12 to 15 years and in school years 8 to 11). For primary schools, school level analysis for 2020 to 2021 only relates to those aged 5 to 10 years. For 2021 to 2022, school level analysis only relates to those aged four to nine years (those now aged 5 to 10 years and in school years 1 to 6) because the majority of these pupils will still be in the same school.Nôl i'r tabl cynnwys
14. Future developments
We will continue to examine the analytical potential of the linked data asset and expand on our existing analysis.Nôl i'r tabl cynnwys
This analysis was produced by the Office for National Statistics (ONS) with support from our School Infection Survey research partners at the London School of Hygiene and Tropical Medicine and UK Health Security Agency.Nôl i'r tabl cynnwys
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