1. Department of Clinical Virology, School of Medicine, University of Crete, 71003 Heraklion, Greece
2. Centre for Neonatal and Paediatric Infection, St. George's, University of London, London SW17 0RE, UK
3. Kliniken Maria Hilf GmbH, 41063 Mönchengladbach, Germany
4. Department of Paediatrics, ‘Penteli’ Children's Hospital, 15236 Palaia Penteli, Greece
5. Paediatric Intensive Care Unit (PICU), University Hospital of Patras, 26504 Rio, Greece
6. COVID‑19 Reference Centre, ‘Rafina’ Health Care Centre, 19009 Rafina, Greece
7. Department of Public Health Policy, School of Public Health, University of West Attica, 11521 Athens, Greece
8. Department of Public Health Policy, School of Public Health, University of West Attica, 11521 Athens
9. Department of Paediatric Radiology, ‘Mitera’ Children's Hospital, 15123 Athens, Greece
10. Hepatitis Virus Diversity Research Unit, Department of Internal Medicine, School of Clinical Medicine, University of the Witwatersrand, 2193 Johannesburg, South Africa
11. Division of Asthma, Allergy and Lung Biology, King's College London, London SE5 9RS, UK
12. First Department of Paediatrics, School of Medicine, University of Athens, 11527 Athens, Greece