Figure 1. Overview of Current Therapies for Covid-19 with Effects on Mortality.

Early stages of infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are characterized by high viral loads in the respiratory tract, which then decrease with progressing disease (red line). Inversely, the levels of inflammatory markers, including the proinflammatory cytokine interleukin-6 and type I interferons, increase with disease severity and respiratory distress (blue line). These observations suggest that antiviral agents are likely to be most effective in early stages of infection during the first week after symptom onset when disease is still mild to moderate. In contrast, immunomodulatory and antiinflammatory treatment is most effective in later stages of disease (ordinal scale score of 4 to 7; see below). Thus far, randomized, controlled trials have shown that treatment with glucocorticoids, Janus kinase inhibitors, and perhaps interleukin-6 receptor antagonists reduces mortality among patients with severe coronavirus disease 2019 (Covid-19). In contrast, antiviral agents have not been shown to have beneficial effects on survival. The ordinal scale of Covid-19 severity refers to definitions from the National Institute of Allergy and Infectious Diseases. The categories of the ordinal scale are as follows: a score of 1 indicates that the patient was not hospitalized, with no limitations on activities; 2, was not hospitalized but had limitation on activities or was receiving supplemental oxygen at home; 3, was hospitalized, without use of supplemental oxygen and no ongoing medical care; 4, was hospitalized and not receiving supplemental oxygen but was receiving ongoing medical care; 5, was hospitalized and receiving supplemental oxygen through low-flow devices; 6, was hospitalized and receiving oxygen through noninvasive ventilation or high-flow oxygen devices; 7, was hospitalized and receiving invasive mechanical ventilation or extracorporeal membrane oxygenation; and 8, died. Category 8 is not shown here.