University of Freiburg - Center for Pediatrics and Adolescent Medicine, Ulm University - Department of Pediatrics and Adolescent Medicine, University of Tübingen - Children's Hospital, Heidelberg University - Department of Pediatrics I, University of Freiburg - Center for Pediatrics and Adolescent Medicine, University of Freiburg - Institute of Medical Biometry and Statistics, University of Freiburg - Center for Pediatrics and Adolescent Medicine, University of Freiburg - Institute for Immunodeficiency, University of Freiburg - Center for Pediatrics and Adolescent Medicine, University of Freiburg - Institute of Virology, University of Tübingen - NMI Natural and Medical Sciences Institute, University of Tübingen - NMI Natural and Medical Sciences Institute, Ulm University - Department of Pediatrics and Adolescent Medicine, Ulm University - Department of Pediatrics and Adolescent Medicine, Ulm University - Department of Pediatrics and Adolescent Medicine, Ulm University - Institute of Virology, Ulm University - Department of Pediatrics and Adolescent Medicine, University of Tübingen - Children's Hospital, University of Tübingen - Children's Hospital, University of Tübingen - Children's Hospital, University of Tübingen - Institute for Clinical Chemistry and Pathobiochemistry, University of Tübingen - Institute for Medical Virology and Epidemiology of Viral Diseases, Heidelberg University - Division of Child Neurology and Metabolic Disorders, Heidelberg University - Department of Pediatrics I, Heidelberg University - Department of Infectious Diseases, Heidelberg University - Department of Infectious Diseases, University of Tübingen - Children's Hospital, Ulm University - Department of Pediatrics and Adolescent Medicine, University of Freiburg - Center for Pediatrics and Adolescent Medicine, Heidelberg University - Department of Pediatrics I and University of Freiburg - Center for Pediatrics and Adolescent Medicine