SARS-CoV-2 infection and transmission in primary schools in England in June–December, 2020 (sKIDs): an active, prospective surveillance study

Shamez Ladhani*, Frances Baawuah, Joanne Beckmann, Ifeanichukwu O. Okike, Shazaad Ahmad, Joanna Garstang, Andrew J. Brent, Bernadette Brent, Jemma Walker, Nicholas Andrews, Georgina Ireland, Felicity Aiano, Zahin Amin-Chowdhury, Louise Letley, Jessica Flood, Samuel E.I. Jones, Raymond Borrow, Ezra Linley, Maria Zambon, John PohVanessa Saliba, Gayatri Amirthalingam, Jamie Lopez Bernal, Kevin Brown, Mary Ramsay

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

57 Citations (Scopus)


Background Little is known about the risk of SARS-CoV-2 infection and transmission in educational settings. Public Health England initiated a study, COVID-19 Surveillance in School KIDs (sKIDs), in primary schools when they partially reopened from June 1, 2020, after the first national lockdown in England to estimate the incidence of symptomatic and asymptomatic SARS-CoV-2 infection, seroprevalence, and seroconversion in staff and students. Methods sKIDs, an active, prospective, surveillance study, included two groups: the weekly swabbing group and the blood sampling group. The swabbing group underwent weekly nasal swabs for at least 4 weeks after partial school reopening during the summer half-term (June to mid-July, 2020). The blood sampling group additionally underwent blood sampling for serum SARS-CoV-2 antibodies to measure previous infection at the beginning (June 1-19, 2020) and end (July 3-23, 2020) of the summer half-term, and, after full reopening in September, 2020, and at the end of the autumn term (Nov 23-Dec 18, 2020). We tested for predictors of SARS-CoV-2 antibody positivity using logistic regression. We calculated antibody seroconversion rates for participants who were seronegative in the first round and were tested in at least two rounds. Findings During the summer half-term, 11 966 participants (6727 students, 4628 staff, and 611 with unknown staff or student status) in 131 schools had 40 501 swabs taken. Weekly SARS-CoV-2 infection rates were 4.1 (one of 24 463; 95% CI 0.1-21.8) per 100 000 students and 12.5 (two of 16 038; 1.5-45.0) per 100 000 staff. At recruitment, in 45 schools, 91 (11.2%; 95% CI 7.9-15.1) of 816 students and 209 (15.1%; 11.9-18.9) of 1381 staff members were positive for SARS-CoV-2 antibodies, similar to local community seroprevalence. Seropositivity was not associated with school attendance during lockdown (p=0.13 for students and p=0.20 for staff) or staff contact with students (p=0.37). At the end of the summer half-term, 603 (73.9%) of 816 students and 1015 (73.5%) of 1381 staff members were still participating in the surveillance, and five (four students, one staff member) seroconverted. By December, 2020, 55 (5.1%; 95% CI 3.8-6.5) of 1085 participants who were seronegative at recruitment (in June, 2020) had seroconverted, including 19 (5.6%; 3.4-8.6) of 340 students and 36 (4.8%; 3.4-6.6) of 745 staff members (p=0.60). Interpretation In England, SARS-CoV-2 infection rates were low in primary schools following their partial and full reopening in June and September, 2020.

Original languageEnglish
Pages (from-to)417-427
Number of pages11
JournalThe Lancet Child and Adolescent Health
Issue number6
Publication statusPublished - Jun 2021

Bibliographical note

Funding Information:
MER reports that the Immunisation and Countermeasures Division (PHE) has provided vaccine manufacturers with post-marketing surveillance reports on pneumococcal and meningococcal infection, which the companies are required to submit to the UK licensing authority in compliance with their risk management strategy. A cost-recovery charge is made for these reports. AJB reports that he is chair of governors of one of the schools included in the study. RB and EL report that the PHE Vaccine Evaluation Unit does contract research on behalf of GlaxoSmithKline, Sanofi, and Pfizer, which is outside the submitted work. JW reports grants from the UK National Institute for Health Research Health Protection Research Unit in Immunisation during the conduct of this study. All other authors declare no competing interests.

Funding Information:
This study was funded by the UK Department of Health and Social Care. We thank all those who contributed to the study; the PHE team, the schools, head teachers, staff, families, and their very brave children who took part in sKIDs. We also thank Sir Jeremy Farrar, Sir Patrick Vallance, members of the UK Department for Education, UK Department of Health and Social Care, London School of Hygiene and Tropical Medicine (London, UK), UK Office for National Statistics, and the UK Scientific Advisory Group for Emergencies for their input and support for sKIDs.

Publisher Copyright:
© 2021 Elsevier Ltd


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