1. From the Division of Paediatric Respiratory Medicine and Allergology, Department of Paediatrics, Inselspital, Bern University Hospital
2. Graduate School for Cellular and Biomedical Sciences, University of Bern, Bern, Switzerland
3. Division of Paediatric Infectious Diseases, Department of Paediatrics, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland.