13Institute for Immunodeficiency, Medical Center Freiburg, Germany and Faculty of Medicine, University of Freiburg, Freiburg, Germany.12Center for Pediatrics and Adolescent Medicine, Medical Center Freiburg, Germany and Faculty of Medicine, University of Freiburg, Freiburg, Germany.11Institute of Clinical Chemistry, Ulm University Medical Center, Ulm, Germany.10Institute of Virology, Ulm University Medical Center, Ulm, Germany.9Red Cross Blood Service Baden-Württemberg-Hessen, Ulm, Germany.8Institute for Clinical Transfusion Medicine and Immunogenetics, Ulm, Germany.7Department of Transfusion Medicine, Ulm University, Ulm, Germany.

6Institute for Medical Virology and Epidemiology of Viral Diseases, University Hospital Tübingen, Tübingen, Germany.5Institute for Clinical Chemistry and Pathobiochemistry, University Hospital Tübingen, Tübingen, Germany.4Center for Clinical Transfusion Medicine Tübingen, Tübingen, Germany.3University Children’s Hospital Tübingen, Tübingen, Germany.2Center for Pediatric Clinical Studies, University Children’s Hospital Tübingen, Tübingen, Germany.1Department of Pediatrics and Adolescent Medicine, Ulm University Medical Center, Ulm University, Ulm, Germany.

Haddad 12 Roland Elling 12,13 Maximilian Stich 14 Burkhard Tönshoff 14 Philipp Henneke 12,13 Klaus-Michael Debatin 1 Axel R. Ales Janda 1 Corinna Engel 2 Jonathan Remppis 3 Sigrid Enkel 4 Andreas Peter 5 Sebastian Hörber 5 Tina Ganzenmueller 6 Sarah Schober 3 Christof Weinstock 7,8,9 Eva-Maria Jacobsen 1 Dorit Fabricius 1 Maria Zernickel 1 Thomas Stamminger 10 Andrea Dietz 10 Hans-Jürgen Groß 11 Sebastian F.

O negative blood and covid 2021