Corticosteroids are immunomodulators that help regulate and normalize the immune system. Corticosteroids were used for treating SARS-CoV, MERS-CoV, and the are now used for treating SARS-CoV-2. However, corticosteroids have the following cons: (1) they delayed the clearance of viral RNA in patients with SARS-CoV and MERS-CoV, and (2) mental illnesses like psychosis can impact some patients taking corticosteroids. Therefore, its efficacy to treat SARS-CoV-2 is still unpredictable.
Sources (all of above information):
Sarma P, Prajapat M, Avti P, Kaur H, Kumar S, Medhi B. Therapeutic options for the treatment of 2019-novel coronavirus: An evidence-based approach. Indian J Pharmacol [serial online] 2020 [cited 2020 Apr 6];52:1-5. Available from: http://www.ijp-online.com/text.asp?2020/52/1/1/280269
Interferons are immunoenhancers that are primarily used to treat hepatitis B. SARS-CoV patients were treated with a combination of interferons and high dosages of corticosteroids (IFN-α + high-dose corticosteroid group). Some studies show that this drug combination reduces the probability of disease-associated oxygen saturation impairment (oxygen saturation impairment: blood does not have the right amount of oxygen).
Sources (all of above information):
Sarma P, Prajapat M, Avti P, Kaur H, Kumar S, Medhi B. Therapeutic options for the treatment of 2019-novel coronavirus: An evidence-based approach. Indian J Pharmacol [serial online] 2020 [cited 2020 Apr 6];52:1-5. Available from: http://www.ijp-online.com/text.asp?2020/52/1/1/280269