Early studies with combination treatments of a type I IFN and IFN- revealed synergistic inhibition of SARS CoV replication in vitro [9][10][11][12].IFN- is a critical regulator linking the innate and adaptive immune responses [13] Moreover, combination treatments with antivirals that target different stages of the virus replicative cycle [14-16] and IFN-2b and IFN- may synergize further to accelerate viral clearance.Accordingly, we conducted a phase II randomized clinical trial to evaluate whether a combination of IFN-2b and IFN-, in addition to standard of care would offer a therapeutic advantage in COVID-19 cases, promoting faster viral clearance and preventing progression to severe disease. Methods Study design and patientsAdult (19-82 yrs), PCR(+) confi rmed SARS-CoV-2 infected cases were enrolled in this open-labeled, single center, prospective, randomized and controlled clinical trial at Military Central Hospital Luis Diaz Soto Hospital, Havana, Cuba.Patients were randomly assigned to receive either subcutaneous treatment with a co-lyophilized combination of 3.0 million international units (MIU) IFN-2b and 0.5 MIU IFN- (HeberFERON®, Cuba Center for Genetic Engineering (CIGB), Havana, Cuba), twice a week for two weeks, or an intramuscular injection of 3.0 MIU