1. Institute for Infectious Diseases, University of Bern, Bern, Switzerland
2. Graduate School for Biomedical Science, University of Bern, Bern, Switzerland
3. Nestlé Institute of Health Sciences, Nestlé Research, Société des Produits Nestlé S.A., Lausanne, Switzerland
4. Division of Respiratory Medicine, Department of Pediatrics, Inselspital, University of Bern, Bern, Switzerland