1. \> 24 hours after confirmation of sars-cov-2 infection by a molecular assay e.g. rt-pcr test (hospital and home settings) or \>24 hours after a positive point-of-care viral infection test (hospital setting only). this criterion does not apply to patients in the hospital setting who had their positive rt-pcr test for sars-cov-2 performed prior to hospitalisation. 2. ≥ 8 days from onset of covid-19 symptoms (cough and/or fever and/or loss or change to sense of smell and/or taste; home setting only). 3. any condition, including findings in the patients' medical history or in the pre-randomisation study assessments that in the opinion of the investigator, constitute a risk or a contraindication for the participation of the patient into the study or that could interfere with the study objectives, conduct or evaluation. 4. current or previous participation in another clinical trial where the patient has received a dose of an investigational medicinal product (imp) containing small molecules within 30 days or 5 half-lives (whichever is longer) prior to entry into this study or containing biologicals within 3 months prior to entry into this study. 5. ventilated or in intensive care. 6. inability to use a nebuliser with a mouthpiece. 7. history of hypersensitivity to natural or recombinant ifn-β or to any of the excipients in the drug preparation. 8. females who are breast-feeding, lactating, pregnant or intending to become pregnant.

1. \> 24 hours after confirmation of sars-cov-2 infection by a molecular assay e.g. rt-pcr test (hospital and home settings) or \>24 hours after a positive point-of-care viral infection test (hospital setting only). this criterion does not apply to patients in the hospital setting who had their positive rt-pcr test for sars-cov-2 performed prior to hospitalisation. 2. ≥ 8 days from onset of covid-19 symptoms (cough and/or fever and/or loss or change to sense of smell and/or taste; home setting only). 3. any condition, including findings in the patients' medical history or in the pre-randomisation study assessments that in the opinion of the investigator, constitute a risk or a contraindication for the participation of the patient into the study or that could interfere with the study objectives, conduct or evaluation. 4. current or previous participation in another clinical trial where the patient has received a dose of an investigational medicinal product (imp) containing small molecules within 30 days or 5 half-lives (whichever is longer) prior to entry into this study or containing biologicals within 3 months prior to entry into this study. 5. ventilated or in intensive care. 6. inability to use a nebuliser with a mouthpiece. 7. history of hypersensitivity to natural or recombinant ifn-β or to any of the excipients in the drug preparation. 8. females who are breast-feeding, lactating, pregnant or intending to become pregnant.

> 24 hours after confirmation of sars-cov-2 infection by a molecular assay e.g. rt-pcr test (hospital and home settings) or >24 hours after a positive point-of-care viral infection test (hospital setting only). this criterion does not apply to patients in the hospital setting who had their positive rt-pcr test for sars-cov-2 performed prior to hospitalisation. ≥ 8 days from onset of covid-19 symptoms (cough and/or fever and/or loss or change to sense of smell and/or taste; home setting only). any condition, including findings in the patients' medical history or in the pre-randomisation study assessments that in the opinion of the investigator, constitute a risk or a contraindication for the participation of the patient into the study or that could interfere with the study objectives, conduct or evaluation. current or previous participation in another clinical trial where the patient has received a dose of an investigational medicinal product (imp) containing small molecules within 30 days or 5 half-lives (whichever is longer) prior to entry into this study or containing biologicals within 3 months prior to entry into this study. ventilated or in intensive care. inability to use a nebuliser with a mouthpiece. history of hypersensitivity to natural or recombinant ifn-β or to any of the excipients in the drug preparation. females who are breast-feeding, lactating, pregnant or intending to become pregnant.

> 24 hours after confirmation of sars-cov-2 infection by a molecular assay e.g. rt-pcr test (hospital and home settings) or >24 hours after a positive point-of-care viral infection test (hospital setting only). this criterion does not apply to patients in the hospital setting who had their positive rt-pcr test for sars-cov-2 performed prior to hospitalisation. ≥ 8 days from onset of covid-19 symptoms (cough and/or fever and/or loss or change to sense of smell and/or taste; home setting only). any condition, including findings in the patients' medical history or in the pre-randomisation study assessments that in the opinion of the investigator, constitute a risk or a contraindication for the participation of the patient into the study or that could interfere with the study objectives, conduct or evaluation. current or previous participation in another clinical trial where the patient has received a dose of an investigational medicinal product (imp) containing small molecules within 30 days or 5 half-lives (whichever is longer) prior to entry into this study or containing biologicals within 3 months prior to entry into this study. ventilated or in intensive care. inability to use a nebuliser with a mouthpiece. history of hypersensitivity to natural or recombinant ifn-β or to any of the excipients in the drug preparation. females who are breast-feeding, lactating, pregnant or intending to become pregnant.

1. > 24 hours after confirmation of sars-cov-2 infection by a molecular assay e.g. rt-pcr test (hospital and home settings) or >24 hours after a positive point-of-care viral infection test (hospital setting only). this criterion does not apply to patients in the hospital setting who had their positive rt-pcr test for sars-cov-2 performed prior to hospitalisation. 2. ≥ 8 days from onset of covid-19 symptoms (cough and/or fever and/or loss or change to sense of smell and/or taste; home setting only). 3. any condition, including findings in the patients' medical history or in the pre-randomisation study assessments that in the opinion of the investigator, constitute a risk or a contraindication for the participation of the patient into the study or that could interfere with the study objectives, conduct or evaluation. 4. current or previous participation in another clinical trial where the patient has received a dose of an investigational medicinal product (imp) containing small molecules within 30 days or 5 half-lives (whichever is longer) prior to entry into this study or containing biologicals within 3 months prior to entry into this study. 5. ventilated or in intensive care. 6. inability to use a nebuliser with a mouthpiece. 7. history of hypersensitivity to natural or recombinant ifn-β or to any of the excipients in the drug preparation. 8. females who are breast-feeding, lactating, pregnant or intending to become pregnant.

1. > 24 hours after confirmation of sars-cov-2 infection by a molecular assay e.g. rt-pcr test (hospital and home settings) or >24 hours after a positive point-of-care viral infection test (hospital setting only). this criterion does not apply to patients in the hospital setting who had their positive rt-pcr test for sars-cov-2 performed prior to hospitalisation. 2. ≥ 8 days from onset of covid-19 symptoms (cough and/or fever and/or loss or change to sense of smell and/or taste; home setting only). 3. any condition, including findings in the patients' medical history or in the pre-randomisation study assessments that in the opinion of the investigator, constitute a risk or a contraindication for the participation of the patient into the study or that could interfere with the study objectives, conduct or evaluation. 4. current or previous participation in another clinical trial where the patient has received a dose of an investigational medicinal product (imp) containing small molecules within 30 days or 5 half-lives (whichever is longer) prior to entry into this study or containing biologicals within 3 months prior to entry into this study. 5. ventilated or in intensive care. 6. inability to use a nebuliser with a mouthpiece. 7. history of hypersensitivity to natural or recombinant ifn-β or to any of the excipients in the drug preparation. 8. females who are breast-feeding, lactating, pregnant or intending to become pregnant.

1. > 24 hours after confirmation of sars-cov-2 infection by a molecular assay e.g. rt-pcr test (hospital and home settings) or >24 hours after a positive point-of-care viral infection test (hospital setting only). this criterion does not apply to patients in the hospital setting who had their positive rt-pcr test for sars-cov-2 performed prior to hospitalisation. 2. >96 hours from onset of covid-19 symptoms (cough and/or fever and/or loss or change to sense of smell and/or taste; home setting only). 3. any condition, including findings in the patients' medical history or in the pre-randomisation study assessments that in the opinion of the investigator, constitute a risk or a contraindication for the participation of the patient into the study or that could interfere with the study objectives, conduct or evaluation. 4. current or previous participation in another clinical trial where the patient has received a dose of an investigational medicinal product (imp) containing small molecules within 30 days or 5 half-lives (whichever is longer) prior to entry into this study or containing biologicals within 3 months prior to entry into this study. 5. ventilated or in intensive care. 6. inability to use a nebuliser with a mouthpiece. 7. history of hypersensitivity to natural or recombinant ifn-β or to any of the excipients in the drug preparation. 8. females who are breast-feeding, lactating, pregnant or intending to become pregnant.

1. > 24 hours after confirmation of sars-cov-2 infection by a molecular assay e.g. rt-pcr test (hospital and home settings) or >24 hours after a positive point-of-care viral infection test (hospital setting only). this criterion does not apply to patients in the hospital setting who had their positive rt-pcr test for sars-cov-2 performed prior to hospitalisation. 2. >96 hours from onset of covid-19 symptoms (cough and/or fever and/or loss or change to sense of smell and/or taste; home setting only). 3. any condition, including findings in the patients' medical history or in the pre-randomisation study assessments that in the opinion of the investigator, constitute a risk or a contraindication for the participation of the patient into the study or that could interfere with the study objectives, conduct or evaluation. 4. current or previous participation in another clinical trial where the patient has received a dose of an investigational medicinal product (imp) containing small molecules within 30 days or 5 half-lives (whichever is longer) prior to entry into this study or containing biologicals within 3 months prior to entry into this study. 5. ventilated or in intensive care. 6. inability to use a nebuliser with a mouthpiece. 7. history of hypersensitivity to natural or recombinant ifn-β or to any of the excipients in the drug preparation. 8. females who are breast-feeding, lactating, pregnant or intending to become pregnant.