1 Division of Paediatric Respiratory Medicine and Allergology, Department of Paediatrics, Inselspital, Bern University Hospital, University of Bern, Freiburgstrasse 15, Bern CH-3010, Switzerland; Graduate School for Health Sciences, University of Bern, Switzerland.
2 Division of Paediatric Respiratory Medicine and Allergology, Department of Paediatrics, Inselspital, Bern University Hospital, University of Bern, Freiburgstrasse 15, Bern CH-3010, Switzerland.
3 Division of Paediatric Respiratory Medicine and Allergology, Department of Paediatrics, Inselspital, Bern University Hospital, University of Bern, Freiburgstrasse 15, Bern CH-3010, Switzerland. Electronic address: kathryn.ramsey@extern.insel.ch.