Evaluation Viral RNA and Virus Infectivity in Exhaled Air Before and After Use of One Dose With ColdZyme Mouth Spray

Inclusion criteria for subject selection: * Male and female subjects above age 18 (inclusive). * Presence of self-reported sudden onset of at least one of the following symptoms of upper respiratory tract infection case definitions for ILI and ARI (as defined by ECDC (EU 2008, 2012, 2022): Cough, sore throat, shortness of breath, non-allergic rhinitis, fever or feverishness, malaise, headache, myalgia. * Otherwise of general good health, according to Investigator's judgement. * Willing and able to give written informed consent for participation in the investigation. Exclusion criteria for subject selection. * Known allergy or hypersensitivity to the components of ColdZyme. * Current use of immunosuppressive therapy within the last 4 weeks prior to Visit 1 and during the investigation. * Diagnosed chronic respiratory disease that could potentially impact the investigation results, according to Investigator's judgement. * Self-reported unhealed wounds/mucosal lesions in the mouth and/or throat. * Participation in another clinical study or investigation within 30 days prior to Visit 1. * Active smokers * The Investigator considers the subject unlikely to comply with investigational procedures, restrictions and requirements.