Interferon-α-2b aerosol inhalation is associated with improved clinical outcomes in patients with coronavirus disease-2019

AIMS: Type 1 interferon (IFN) is used to treat patients with coronavirus disease-2019 (COVID-19) but robust supporting evidence is lacking. We investigated the association between IFN-α-2b and the clinical outcomes of patients with COVID-19. METHODS: A total of 1401 patients were enrolled, with 852 (60.8%) patients receiving 5 000 000 U of IFN-α-2b via aerosol inhalation twice daily. The primary outcome was a composite measure consisting of mechanical ventilation, intensive care unit (ICU) admission and death. A subgroup analysis was performed to investigate the impact of the IFN-α-2b initiation schedule on symptom onset. RESULTS: The risk probability for crude endpoints was lower in the IFN-α-2b group (3.8%) than in the non-IFN-α-2b group (9.3%, P < .001). After adjusting the confounding factors, IFN-α-2b therapy achieved a reduction of 64% in occurrence of endpoint events (hazard ratio, 0.36; 95% confidence interval [CI], 0.21-0.62). In the subgroup analysis, compared with patients who received IFN-α-2b treatment 0-2 days after symptom onset, the hazard ratio for endpoints was 2.2 (95% CI, 0.43-11.13) in patients who received the therapy 3-5 days after symptom onset, 5.89 (95% CI, 0.99-35.05) in patients who received the therapy 6-8 days after symptom onset, and remained at a high level thereafter. CONCLUSIONS: IFN-α-2b aerosol inhalation therapy may be associated with improved clinical outcomes in patients with COVID-19, and delayed IFN-α-2b intervention was associated with increased probabilities of risk events. Further randomized clinical trials are needed to validate the preliminary findings of this study.