4.5 Interferon-α and -β
Human immune system fight against viral infections by release interferon (Alpha, Beta), which inhibits the proliferation of viruses by inducing the synthesis of antiviral proteins. Interferon drugs are used as a broad-spectrum antiviral drug in clinical practice. Previous study has demonstrated that interferon-α and -β showed antiviral activity against MERS (Morra et al., 2018; Stockman, Bellamy, & Garner, 2006). A study demonstrated the antiviral effects of interferon-α2β and ribavirin on the replication of nCoV isolates hCoV-EMC / 2012 in Vero and LLC-MK2 cells (Falzarano et al., 2013). National Health Commission issued the “Diagnosis and treatment protocol for novel coronavirus pneumonia (version 7)”, which recommend that interferon alpha is taken by atomization inhalation. Adults should take 50μg in 2ml of sterile water via injection each time twice a day. Interferon alpha can be used as a novel drug to improve virus clearance effect of the respiratory mucosa of patients (Commission, 2020). Currently, a multi-center, blank-controlled, randomized, open, multi-stage clinical study is ongoing aimed at evaluating the efficacy and safety of recombinant human interferon α1β in treating patients with COVID-19 in Wuhan (NCT04293887) (ClinicalTrails.gov, 2020). However, there is no data on animal or human studies to recommend their clinincal use to combat COVID-19. Further verification of its safety and efficacy is required.
4.6 Corticosteroids
Acute lung injury (ALI) or ARDS was seen in cases of late phase severe SARS. Corticosteroids were adopted to suppress lung inflammation in MERS and SARS due to their immunomodulatory properties. Some clinical trials suggested that high-dose of corticosteroids reduced mortality of SARS without increasing the risk of life-threatening complications (Ho et al., 2003; Sung et al., 2004; Zhong, 2004). A retrospective study on adverse outcomes of SARS patients with hormone therapy showed that patients developed adverse reactions, and hormone therapy increased the risk of admission to the intensive care unit or death by 20.7 times (Auyeung et al., 2005). Elsewhere, a retrospective study showed that appropriate use of hormones in patients with severe SARS can reduce mortality and shorten hospital stay. Moreover, they found that hormones did not cause serious secondary lower respiratory tract infections and other complications (R. C. Chen et al., 2006). In February, 7, 2020, an article published on the Lancet suggested that it is insufficient for current clinical evidence to support the hormone therapy in treating ALI resulting from SARS-CoV-2 (Russell, Millar, & Baillie, 2020). Following the epidemic of SARS, the efficacy and safety of glucocorticoids is considerably understood. Corticosteroids should be used with caution for patients with COVID-19. Furthermore, physicians should strictly follow the indications, drug dosage and course of treatment. However, for critically ill patients with rapid progression, appropriate use of corticosteroids in addition to a ventilator support should be measured to prevent the progression of acute respiratory distress syndrome.