The current study will investigate the tolerability and efficacy of inhaled Carragelose® versus saline in hospitalized COVID-19 patients. As SARS-CoV-2 replicates readily in the lung, it is planed to apply Carragelose® in an inhalative form. Hospitalized COVID-19 patients with respiratory symptoms will inhale Inhaleen for 5 days.

The tolerability and efficacy of inhaled Carragelose® will be investigated in a randomized, double blind, placebo-controlled trial in hospitalized COVID-19 patients.

Patients will inhale Inhaleen or Placebo 3 times a day for 7 minutes for 5 days.

The primary objective of the trial is to demonstrate that Inhaleen inhalation improves the clinical status of hospitalized COVID-19 patients on day 8 compared to placebo inhalation.

Inclusion Criteria:

• Written informed consent obtained before any trial related procedures are performed
• Age ≥ 18 years
• Hospitalized patients with PCR confirmed SARS-CoV-2 infection and symptom onset ≤ 10 days before randomization
• Patients with respiratory COVID-19 symptoms
• Randomization ≤ 48h from admission
• Peripheral capillary oxygen saturation (SpO2) ≥ 90% on room air or supplemental oxygen at screening
• Patient agrees to refrain from taking other carragelose products (e.g. throat spray, lozenges)

Exclusion Criteria:

• No informed consent
• Persistent hypoxemia with SpO2 < 90% despite supplemental oxygen of > 6LO2/min at screening.
• Patients with predominantly extrapulmonary COVID-19 symptoms (e.g. gastrointestinal, neurological, etc.)
• Subjects who demonstrate respiratory and/or cardiac instability that is considered by the investigator as a reason for exclusion. Additionally, any other clinically significant disease that could interfere with participation in the study, with the intervention being studied, or with the evaluation of symptoms. Specific exclusions are asthma, immune deficiency, autoimmune disease, clinically significant cardiovascular, endocrinological, neurological, respiratory, gastrointestinal disease or any disease that is considered by the investigator as a reason for exclusion.
• Known hypersensitivity or allergy to any component of the test product
• The subject is related to any study personnel or has any other close ties or conflicts of interest with the study sponsor.
• The subject has received any investigational drug or participated in a clinical trial within 4 weeks of entry to this study
• Current medication other than oral contraception,that is considered by the investigator as a reason for exclusion.
• Pregnant/lactating women at the time of recruitment will be excluded from the study
• Participation in another antiviral clinical trial

double blinded