1. Institute of Clinical Medicine; University of Helsinki; Helsinki Finland
2. Department of Vaccination and Immune Protection; National Institute for Health and Welfare; Helsinki Finland
3. Environmental Health Department; National Institute for Health and Welfare; Kuopio Finland
4. Department of Medical Microbiology; University of Groningen; University Medical Center Groningen; Groningen The Netherlands
5. Christine Kühne - Center for Allergy Research and Education (CK-CARE); Davos Switzerland
6. Children's Hospital; University of Zurich; Zurich Switzerland
7. The Department of Respiratory Disease; Université de Franche-Comté; UMR-CNRS Chrono-Environnement; University Hospital; Besançon France
8. Institute of Epidemiology and Medical Biometry; Ulm University; Ulm Germany
9. Children's Hospital of Eastern Switzerland; St. Gallen Switzerland
10. Children and Young Adults’ Medicine; Children's Hospital; Schwarzach Austria
11. Dr. von Hauner Children's Hospital of the Ludwig Maximilian University Munich; Munich Germany
12. Comprehensive Pneumology Center Munich (CPC-M); Member of the German Center for Lung Research; Mölndal Sweden
13. Respiratory, Inflammation and Autoimmunity, Innovative Medicine; AstraZeneca R & D; Mölndal Sweden