subjects who meet any of the following criteria will be excluded from the study: 1. haemoglobin a1c ≥6.0% or 42 mmol/mol 2. forced expiratory volume in 1 second (fev1) less than 80% predicted value 3. signs or symptoms suggestive of upper or lower respiratory tract infection (including fever or persistent cough) within 28 days of day 1 4. pregnant, possibly pregnant, or lactating women 5. women who have been pregnant through the third trimester or given birth within the past 6 months 6. planning a pregnancy (subject or partner) within 90 days after the last imp dose 7. inadequate venous access for repeated phlebotomy 8. history of confirmed or suspected sars-cov-2 infection 9. contact with any individual subsequently confirmed to have sars-cov-2 within 14 days after contact 10. history of wheeze treated with inhaler(s) 11. respiratory symptoms, including wheeze, that have ever resulted in hospitalisation 12. known bronchial hyperreactivity to viruses 13. any significant abnormality altering the anatomy of the nose in a substantial way or nasopharynx that may interfere with the aims of the study and in particular any of the nasal assessments or viral challenge (historical nasal polyps can be included, but large nasal polyps causing current and significant symptoms and/or requiring regular treatments in the last month are excluded)

subjects who meet any of the following criteria will be excluded from the study: 1. haemoglobin a1c ≥6.0% or 42 mmol/mol 2. forced expiratory volume in 1 second (fev1) less than 80% predicted value 3. signs or symptoms suggestive of upper or lower respiratory tract infection (including fever or persistent cough) within 28 days of day 1 4. pregnant, possibly pregnant, or lactating women 5. women who have been pregnant through the third trimester or given birth within the past 6 months 6. planning a pregnancy (subject or partner) within 90 days after the last imp dose 7. inadequate venous access for repeated phlebotomy 8. history of confirmed or suspected sars-cov-2 infection 9. contact with any individual subsequently confirmed to have sars-cov-2 within 14 days after contact 10. history of wheeze treated with inhaler(s) 11. respiratory symptoms, including wheeze, that have ever resulted in hospitalisation 12. known bronchial hyperreactivity to viruses 13. any significant abnormality altering the anatomy of the nose in a substantial way or nasopharynx that may interfere with the aims of the study and in particular any of the nasal assessments or viral challenge (historical nasal polyps can be included, but large nasal polyps causing current and significant symptoms and/or requiring regular treatments in the last month are excluded)

subjects who meet any of the following criteria will be excluded from the study: haemoglobin a1c ≥6.0% or 42 mmol/mol forced expiratory volume in 1 second (fev1) less than 80% predicted value signs or symptoms suggestive of upper or lower respiratory tract infection (including fever or persistent cough) within 28 days of day 1 pregnant, possibly pregnant, or lactating women women who have been pregnant through the third trimester or given birth within the past 6 months planning a pregnancy (subject or partner) within 90 days after the last imp dose inadequate venous access for repeated phlebotomy history of confirmed or suspected sars-cov-2 infection contact with any individual subsequently confirmed to have sars-cov-2 within 14 days after contact history of wheeze treated with inhaler(s) respiratory symptoms, including wheeze, that have ever resulted in hospitalisation known bronchial hyperreactivity to viruses any significant abnormality altering the anatomy of the nose in a substantial way or nasopharynx that may interfere with the aims of the study and in particular any of the nasal assessments or viral challenge (historical nasal polyps can be included, but large nasal polyps causing current and significant symptoms and/or requiring regular treatments in the last month are excluded)

subjects who meet any of the following criteria will be excluded from the study: haemoglobin a1c ≥6.0% or 42 mmol/mol forced expiratory volume in 1 second (fev1) less than 80% predicted value signs or symptoms suggestive of upper or lower respiratory tract infection (including fever or persistent cough) within 28 days of day 1 pregnant, possibly pregnant, or lactating women women who have been pregnant through the third trimester or given birth within the past 6 months planning a pregnancy (subject or partner) within 90 days after the last imp dose inadequate venous access for repeated phlebotomy history of confirmed or suspected sars-cov-2 infection contact with any individual subsequently confirmed to have sars-cov-2 within 14 days after contact history of wheeze treated with inhaler(s) respiratory symptoms, including wheeze, that have ever resulted in hospitalisation known bronchial hyperreactivity to viruses any significant abnormality altering the anatomy of the nose in a substantial way or nasopharynx that may interfere with the aims of the study and in particular any of the nasal assessments or viral challenge (historical nasal polyps can be included, but large nasal polyps causing current and significant symptoms and/or requiring regular treatments in the last month are excluded)

subjects who meet any of the following criteria will be excluded from the study: 1. haemoglobin a1c ≥6.0% or 42 mmol/mol 2. forced expiratory volume in 1 second (fev1) less than 80% predicted value 3. signs or symptoms suggestive of upper or lower respiratory tract infection (including fever or persistent cough) within 28 days of day 1 4. pregnant, possibly pregnant, or lactating women 5. women who have been pregnant through the third trimester or given birth within the past 6 months 6. planning a pregnancy (subject or partner) within 90 days after the last imp dose 7. inadequate venous access for repeated phlebotomy 8. history of confirmed or suspected sars-cov-2 infection 9. contact with any individual subsequently confirmed to have sars-cov-2 within 14 days after contact 10. history of wheeze treated with inhaler(s) 11. respiratory symptoms, including wheeze, that have ever resulted in hospitalisation 12. known bronchial hyperreactivity to viruses 13. any significant abnormality altering the anatomy of the nose in a substantial way or nasopharynx that may interfere with the aims of the study and in particular any of the nasal assessments or viral challenge (historical nasal polyps can be included, but large nasal polyps causing current and significant symptoms and/or requiring regular treatments in the last month are excluded)

subjects who meet any of the following criteria will be excluded from the study: 1. haemoglobin a1c ≥6.0% or 42 mmol/mol 2. forced expiratory volume in 1 second (fev1) less than 80% predicted value 3. signs or symptoms suggestive of upper or lower respiratory tract infection (including fever or persistent cough) within 28 days of day 1 4. pregnant, possibly pregnant, or lactating women 5. women who have been pregnant through the third trimester or given birth within the past 6 months 6. planning a pregnancy (subject or partner) within 90 days after the last imp dose 7. inadequate venous access for repeated phlebotomy 8. history of confirmed or suspected sars-cov-2 infection 9. contact with any individual subsequently confirmed to have sars-cov-2 within 14 days after contact 10. history of wheeze treated with inhaler(s) 11. respiratory symptoms, including wheeze, that have ever resulted in hospitalisation 12. known bronchial hyperreactivity to viruses 13. any significant abnormality altering the anatomy of the nose in a substantial way or nasopharynx that may interfere with the aims of the study and in particular any of the nasal assessments or viral challenge (historical nasal polyps can be included, but large nasal polyps causing current and significant symptoms and/or requiring regular treatments in the last month are excluded)