Novel Mucosal Correlates Of RSV Protection In Older Adults

Inclusion Criteria: * Healthy persons aged 65 to 75 years, able to give informed consent * Non-smokers or ex-smokers with a pack year history of 10 or less * Spirometry within the normal range for age and height (+/- 15%) * Forced Expiratory Volume / Forced Vital Capacity (FEV1/FVC) \>70% without bronchodilator * Vaccination against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) at the minimum of 4 weeks prior to screening Exclusion Criteria: * Chronic respiratory disease (asthma, chronic obstructive pulmonary disease, rhinitis, sinusitis) in adulthood * Inhaled bronchodilator or steroid use within the last 12 months * Habitual use of any medication or other product (prescription or over the counter) for symptoms of rhinitis or nasal congestion within the last 3 months * Acute upper respiratory infection (URI or sinusitis) in the past 6 weeks * Participants with allergic symptoms present at baseline * Clinically relevant abnormality on chest X-ray * Those in close domestic contact (i.e. sharing a household with, caring for, or daily face to face contact) with children under 3 years, clinically vulnerable and/or immunosuppressed persons, or those with chronic respiratory disease * Participants with known or suspected immune deficiency * Receipt of systemic glucocorticoids (in a dose ≥ 5 mg prednisone daily or equivalent) within one month, or any other cytotoxic or immunosuppressive drug within 6 months prior to challenge * Known Immunoglobulin A (IgA) deficiency, immotile cilia syndrome, or Kartagener's syndrome * History of frequent nose bleeds * Any significant medical condition or prescribed drug deemed by a study doctor to make the participant unsuitable for the study * Recent or current use of recreational drugs, confirmed by a positive urine drug screen * History of difficult blood draw, syncope or poor tolerance of sampling procedures