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

doi:10.3390/children9050652

Illness Characteristics of COVID-19 in Children Infected with the SARS-CoV-2 Delta Variant

Children (Basel). 2022 May 3;9(5):652. doi: 10.3390/children9050652.

Authors

Erika Molteni¹, Carole H Sudre^{1

2

3}, Liane Dos Santos Canas¹, Sunil S Bhopal⁴, Robert C Hughes⁵, Liyuan Chen¹, Jie Deng¹, Benjamin Murray¹, Eric Kerfoot¹, Michela Antonelli¹, Mark Graham¹, Kerstin Kläser¹, Anna May⁶, Christina Hu⁶, Joan Capdevila Pujol⁶, Jonathan Wolf⁶, Alexander Hammers^{1

7}, Timothy D Spector⁸, Sebastien Ourselin¹, Marc Modat¹, Claire J Steves^{8

9}, Michael Absoud^{10

11}, Emma L Duncan^{8

12}

Affiliations

¹ School of Biomedical Engineering & Imaging Sciences, King's College London, London WC2R 2LS, UK.
² MRC Unit for Lifelong Health and Ageing, Department of Population Health Sciences, University College London, London WC1E 6BT, UK.
³ Centre for Medical Image Computing, Department of Computer Science, University College London, London WC1E 6BT, UK.
⁴ Population Health Sciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne NE1 7RU, UK.
⁵ Department of Population Health, Faculty of Epidemiology & Population Health, London School of Hygiene & Tropical Medicine, Keppel Street, London WC1E 7HT, UK.
⁶ ZOE Limited London, London SE1 7RW, UK.
⁷ King's College London & Guy's and St Thomas' PET Centre, London WC2R 2LS, UK.
⁸ Department of Twin Research and Genetic Epidemiology, King's College London, London WC2R 2LS, UK.
⁹ Department of Aging and Health, Guy's and St Thomas' NHS Foundation Trust, London SE1 7EH, UK.
¹⁰ Children's Neurosciences, Evelina London Children's Hospital, St Thomas' Hospital, King's Health Partners, Academic Health Science Centre, London SE1 7EH, UK.
¹¹ Department of Women and Children's Health, Faculty of Life Sciences and Medicine, School of Life Course Sciences, King's College London, London WC2R 2LS, UK.
¹² Department of Endocrinology, Guy's and St Thomas' NHS Foundation Trust, London SE1 7EH, UK.

Abstract

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.

Keywords: COVID-19 symptoms; SARS-CoV-2 B.1.1.7 variant; SARS-CoV-2 B.1.617.2 variant; SARS-CoV-2 Delta strain; paediatric COVID-19.

Abstract

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