1. Laboratory of Clinical Virology, Medical School, University of Crete, 71003 Heraklion, Greece
2. Hepatitis Virus Diversity Research Unit, Department of Internal Medicine, School of Clinical Medicine, University of the Witwatersrand, 2193 Johannesburg, South Africa
3. Third Department of Paediatrics, National and Kapodistrian University of Athens School of Medicine, General University Hospital ‘ATTIKON’, 12462 Athens, Greece
4. Department of Medicine, Rutgers/Saint Peter's University Hospital, New Brunswick, NJ 08901, USA
5. Faculty of Medicine, Pavol Jozef Safarik University, 040 11 Košice, Slovak Republic
6. The Yale Larynx Laboratory, Department of Surgery, Yale School of Medicine, New Haven, CT 06510, USA
7. Department of Pediatrics, General Hospital ‘TZANEIO’, 18536 Piraeus, Greece
8. First Academic Department of Pneumonology, National and Kapodistrian University of Athens School of Medicine, 11527 Athens, Greece
9. Neonatal Unit, Division for Women and Children's Health, Noble's Hospital, IM4 4RJ Douglas, Isle of Man
10. First Department of Paediatrics, National and Kapodistrian University of Athens School of Medicine, 11527 Athens, Greece
11. St. George's, University of London, London SW17 0RE, UK
12. COVID‑19 Reference Centre, ‘Rafina’ Health Care Centre, 19009 Rafina, Greece
13. Paediatric Intensive Care Unit (PICU), University Hospital of Patras, 26504 Rio, Greece
14. Department of Women and Children's Health, School of Life Course Sciences and Medicine, King's College London, London SE5 9RS, UK