Study aim: Evaluating efficacy of Kelofan syrup on pulmonary & other clinical and laboratory manifestations of patients with probable or confirmed COVID-19 Design: This pilot clinical trial will be performed on 15 hospitalized patients with probable or confirmed COVID-19, as before-after trial without any control group. Settings and conduct: This study will be carried out at Imam Khomeini Hospital, one of the hospitals affiliated to Ardabil University of Medical Sciences. This hospital has been assigned for COVID-19 patients. This research will be carried out in April of 2020. Participants/Inclusion and exclusion criteria: Inclusion criteria: Patients over 18 years old hospitalized with or probable of COVID-19 based on Radiological findings or Positive PCR test according to the instructions of the Ministry of Health; Clinically classified as moderate and severe, no need for intubation; written and informed satisfaction of patients Non-inclusion: Liver, kidney and heart failure; History of allergies to medicinal herbs; Immunodeficiency; Hypertension; Diabetes; Alcohol or drug addiction Intervention groups: Patients are receiving a herbal formulation (Kelofan syrup) in form of a syrup at a dose of 7.5 cc two times a day for a maximum of seven days, in addition to standard treatment. Main outcome variables: Respiratory rate per minute; O2 Saturation