Inclusion Criteria:  Confirmed by PCR test SARS-CoV-2 infection (according to nationally authorized laboratory criteria) Hospitalized patient with COVID-19 of moderate stable or worsening severity not requiring ICU admission (defined by NIH criteria - fever, cough, dyspnea, fast breathing, but no signs of severe pneumonia, including SpO2 ≥ 94% on room air). Age: 18 years old and above. Subjects must be hospitalized Ability to receive treatment by spray into the oral cavity  Exclusion Criteria:  Tube feeding or parenteral nutrition. Patients with scores 5 or above per the Ordinal Scale for Clinical Improvement published by the WHO. (i.e., who need oxygen supply beyond use of nozzles or simple mask) Need for admission to ICU during the present hospitalization at any time prior to completion of the recruitment to the study. Any condition which, in the opinion of the Principal Investigator, would prevent full participation in this trial or would interfere with the evaluation of the trial endpoints.