1. Allergy Department; 2nd Pediatric Clinic; National and Kapodistrian University of Athens; Athens Greece
2. Upper Airway Research Laboratory; Ghent University Hospital; Ghent Belgium
3. Department of Molecular Pneumology; Friedrich-Alexander-Universität Erlangen-Nürnberg; Universitätsklinikum Erlangen; Erlangen Germany
4. Department of Pediatrics; Turku University Hospital and University of Turku; Turku Finland
5. Department of Allergy and Clinical Immunology; 424 General Military Training Hospital; Thessaloniki Greece
6. Department of Pediatrics and Adolescent Medicine; Department of Allergy and Pneumology; Children's Hospital; Friedrich-Alexander-Universität Erlangen-Nürnberg; Universitätsklinikum Erlangen; Erlangen Germany
7. Department of Immunology, Rheumatology and Allergy; Central University Hospital; Lodz Poland
8. Department of Rheumatology; Medical University of Lodz; Lodz Poland
9. Department of Clinical Virology; Turku University Hospital; Department of Virology; Turku University; Turku Finland
10. Division of Infection; Immunity & Respiratory Medicine; University of Manchester; Manchester UK