* Study procedure will be carried out after informed consent is obtained.
* Baseline physical exam and laboratory investigations will be performed.
* Eligible patients will be randomized to one of the two treatment arms.
* Symptoms and signs will be monitored daily.
* NP swab will be done at day5-7, and prior to discharge.
* Complete blood counts, blood chemistries, electrocardiography will be performed for adverse event monitoring within 5 days after end of study drugs' administration.
* Patients will be discharged at 2- 4 weeks after hospitalization, according to PCR results.
* There will be 1-2 follow up visit at out patient clinic for NP swab (patients with +ve last NP swab before discharge), and blood tests.
* Additional 5-8 ml. of EDTA blood will be taken at baseline and weekly for antibody detection.
* Interim analysis of both safety and efficacy will be performed when approximately 50% of enrollment is achieved.
* Intention to treat analysis is planned at the completion of enrollment.
