Conflict of interest: R. Djukanovic reports receiving fees for lectures at symposia organised by Novartis, AstraZeneca and TEVA, consultation for TEVA and Novartis as member of advisory boards, and participation in a scientific discussion about asthma organised by GlaxoSmithKline. He is a co-founder and current consultant, and has shares in Synairgen, a University of Southampton spin out company. Conflict of interest: I.M. Adcock has nothing to disclose. Conflict of interest: G. Anderson reports grants from Pieris Pharmaceuticals (research grant on inhaled anticalins), personal fees from Pieris Pharmaceuticals (consultancy on inhaled anticalins), other from AstraZeneca (during 2016 he worked on secondment from his university as a visiting chief scientist), personal fees from ENA (consultancy on TLR2 agonists), personal fees from AstraZeneca/Medimmune (consultancy on respiratory franchise and involvement in Novelty clinical trial), personal fees from Orbimed (consultancy on respiratory projects), personal fees from Novartis (consultancy on respiratory portfolio), personal fees from Menarini (speakers’ fee), grants from GSK (untied grant to the University of Melbourne), and personal fees from GSK (advisory board), outside the submitted work. In addition, G. Anderson has a patent for a method of treatment licensed to GSK. Conflict of interest: E.H. Bel reports grants for research and/or personal fees from GSK, Novartis, AstraZeneca, Teva, Sanofi Regeneron, Vectura, Boehringer, and Roche. Conflict of interest: G.W. Canonica has received personal fees from AstraZeneca, Sanofi, Regeneron, Novartis, Boehringer Ingelheim, Chiesi Farmaceutici, Mundipharma, Orion and Menarini, and research grants from AstraZeneca, Novartis, GSK, Sanofi Regeneron. Conflict of interest: H. Cao has nothing to disclose. Conflict of interest: K.F. Chung reports grants and personal fees from GlaxoSmithKline (advisory board meeting), personal fees from AstraZeneca (advisory board meeting and speakers’ bureau), personal fees from Novartis (advisory board meeting and speakers’ bureau), grants and personal fees from Merck (speakers’ bureau), personal fees from Boehringer Ingelheim (advisory board meeting), and personal fees from TEVA (advisory board meeting), outside the submitted work. Conflict of interest: D.E. Davies reports personal fees from Synairgen (consultant and shareholder), outside the submitted work. In addition, D.E. Davies has a patent “Interferon beta for virus-induced asthma exacerbations” licensed to Synairgen. Conflict of interest: C. Genton is an employee of the European Respiratory Society. In addition, C. Genton reports multi-sponsored study fees from Chiesi, Sanofi, Grifols, Novartis, Insmed, Zambon, TEVA and GlaxoSmithKline outside the submitted work. Conflict of interest: T. Gibson-Latimer reports that she is a lay reviewer and lay panel member for Asthma UK. Conflict of interest: D. Hamerlijnck is an Independent European Federation of Allergy and Airways Diseases Patients’ Associations (EFA) patient expert for Novartis Global Drug Development Chief Medical Office. Conflict of interest: E. Heuvelin is an employee of the European Respiratory Society. In addition, E. Heuvelin reports multi-sponsored study fees from Chiesi, Sanofi, Grifols, Novartis, Insmed, Zambon, TEVA and GlaxoSmithKline outside the submitted work. Conflict of interest: R. Louis reports grants from GSK, Novartis and Chiesi, and grants and personal fees from AstraZeneca, outside the submitted work. Conflict of interest: S. Korn has nothing to disclose. Conflict of interest: M. Kots reports personal fees from Chiesi Farmaceutici (company employee; Global clinical development department), outside the submitted work. Conflict of interest: N. Kwon has nothing to disclose. Conflict of interest: R. Naddaf is a TEVA Pharmaceuticals Netherlands employee. Conflict of interest: S.S. Wagers reports consulting fees from Kings College Hospital NHS Foundation Trust, Academic Medical Research AMC, Medical Research BV Asthma UK, Athens Medical School, Boehringer Ingelheim International GmbH, CHU de Toulouse, CIRO, DS Biologicls Ltd, École Polytechnique Fédérele de Lausanne, European Respiratory Society, FISEVI, Fluidic Analytics Ltd., Fraunhofer IGB, Fraunhofer ITEM, GlaxosmithKline Research & Dev Ltd, Holland & Knight, Karolinska Institutet Fakturor, KU Leuven Longfonds, National Heart & Lung Institute, Novartis Pharma AG, Owlstone Medical Limited, PExA AB, UCB Biopharma S.P.R.L., UCB Biosciences GmbH, Umeå University, Univ. Hosptial Southampton NHS Foundation Trust, Università Campus Bio-Medico di Roma, Universita Cattolica Del Sacro Cuore, Universität Ulm, University of Bern, University of Edinburgh, University of Hull, University of Leicester, University of Loughborough, University of Luxembourg, University of Manchester, University of Notthingham, Vlaams Brabant, Dienst Europa.