Illness Characteristics of COVID-19 in Children Infected with the SARS-CoV-2 Delta Variant
Erika Molteni,
Carole H. Sudre,
Liane Dos Santos Canas,
Sunil S. Bhopal,
Robert C. Hughes,
Liyuan Chen,
Jie Deng,
Benjamin Murray,
Eric Kerfoot,
Michela Antonelli,
Mark Graham,
Kerstin Kläser,
Anna May,
Christina Hu,
Joan Capdevila Pujol,
Jonathan Wolf,
Alexander Hammers,
Timothy D. Spector,
Sebastien Ourselin,
Marc Modat,
Claire J. Steves,
Michael Absoud,
Emma L. Duncan
Affiliations
Erika Molteni
School of Biomedical Engineering & Imaging Sciences, King’s College London, London WC2R 2LS, UK
Carole H. Sudre
School of Biomedical Engineering & Imaging Sciences, King’s College London, London WC2R 2LS, UK
Liane Dos Santos Canas
School of Biomedical Engineering & Imaging Sciences, King’s College London, London WC2R 2LS, UK
Sunil S. Bhopal
Population Health Sciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE1 7RU, UK
Robert C. Hughes
Department of Population Health, Faculty of Epidemiology & Population Health, London School of Hygiene & Tropical Medicine, Keppel Street, London WC1E 7HT, UK
Liyuan Chen
School of Biomedical Engineering & Imaging Sciences, King’s College London, London WC2R 2LS, UK
Jie Deng
School of Biomedical Engineering & Imaging Sciences, King’s College London, London WC2R 2LS, UK
Benjamin Murray
School of Biomedical Engineering & Imaging Sciences, King’s College London, London WC2R 2LS, UK
Eric Kerfoot
School of Biomedical Engineering & Imaging Sciences, King’s College London, London WC2R 2LS, UK
Michela Antonelli
School of Biomedical Engineering & Imaging Sciences, King’s College London, London WC2R 2LS, UK
Mark Graham
School of Biomedical Engineering & Imaging Sciences, King’s College London, London WC2R 2LS, UK
Kerstin Kläser
School of Biomedical Engineering & Imaging Sciences, King’s College London, London WC2R 2LS, UK
Anna May
ZOE Limited London, London SE1 7RW, UK
Christina Hu
ZOE Limited London, London SE1 7RW, UK
Joan Capdevila Pujol
ZOE Limited London, London SE1 7RW, UK
Jonathan Wolf
ZOE Limited London, London SE1 7RW, UK
Alexander Hammers
School of Biomedical Engineering & Imaging Sciences, King’s College London, London WC2R 2LS, UK
Timothy D. Spector
Department of Twin Research and Genetic Epidemiology, King’s College London, London WC2R 2LS, UK
Sebastien Ourselin
School of Biomedical Engineering & Imaging Sciences, King’s College London, London WC2R 2LS, UK
Marc Modat
School of Biomedical Engineering & Imaging Sciences, King’s College London, London WC2R 2LS, UK
Claire J. Steves
Department of Twin Research and Genetic Epidemiology, King’s College London, London WC2R 2LS, UK
Michael Absoud
Children’s Neurosciences, Evelina London Children’s Hospital, St Thomas’ Hospital, King’s Health Partners, Academic Health Science Centre, London SE1 7EH, UK
Emma L. Duncan
Department of Twin Research and Genetic Epidemiology, King’s College London, London WC2R 2LS, UK
Background: The Delta (B.1.617.2) SARS-CoV-2 variant was the predominant UK circulating strain between May and November 2021. We investigated whether COVID-19 from Delta infection differed from infection with previous variants in children. Methods: Through the prospective COVID Symptom Study, 109,626 UK school-aged children were proxy-reported between 28 December 2020 and 8 July 2021. We selected all symptomatic children who tested positive for SARS-CoV-2 and were proxy-reported at least weekly, within two timeframes: 28 December 2020 to 6 May 2021 (Alpha (B.1.1.7), the main UK circulating variant) and 26 May to 8 July 2021 (Delta, the main UK circulating variant), with all children unvaccinated (as per national policy at the time). We assessed illness profiles (symptom prevalence, duration, and burden), hospital presentation, and presence of long (≥28 day) illness, and calculated odds ratios for symptoms presenting within the first 28 days of illness. Results: 694 (276 younger (5–11 years), 418 older (12–17 years)) symptomatic children tested positive for SARS-CoV-2 with Alpha infection and 706 (227 younger and 479 older) children with Delta infection. Median illness duration was short with either variant (overall cohort: 5 days (IQR 2–9.75) with Alpha, 5 days (IQR 2–9) with Delta). The seven most prevalent symptoms were common to both variants. Symptom burden over the first 28 days was slightly greater with Delta compared with Alpha infection (in younger children, 3 (IQR 2–5) symptoms with Alpha, 4 (IQR 2–7) with Delta; in older children, 5 (IQR 3–8) symptoms with Alpha, 6 (IQR 3–9) with Delta infection ). The odds of presenting several symptoms were higher with Delta than Alpha infection, including headache and fever. Few children presented to hospital, and long illness duration was uncommon, with either variant. Conclusions: COVID-19 in UK school-aged children due to SARS-CoV-2 Delta strain B.1.617.2 resembles illness due to the Alpha variant B.1.1.7., with short duration and similar symptom burden.
