“Interferons are our first line of defence against any and all viruses – but viruses such as corona-viruses have co-evolved to very specifically block an interferon response”, said lead author Dr Eleanor Fish of the Toronto General Hospital Research Institute & University of Toronto’s Department of Immunology. “This informs us of the importance of interferons for the clearance of virus infections. Treatment with interferon will override the inhibitory effects of the virus,” he noted.
Earlier study on SARS helped
Fish and his team of doctors considered IFN-α therapy for COVID-19 based on their earlier findings during the 2003 SARS outbreak. “My group conducted a clinical study in Toronto to evaluate the therapeutic potential of IFN-α against SARS. Our findings were that interferon treatment sped up the resolution of lung abnormalities in patients treated with interferon compared with those not treated with interferon” said Fish.
The authors examined the course of disease in a group of 77 individuals with confirmed COVID-19 and admitted to Union Hospital, Tongii Medical College, Wuhan in China, between January 16 and February 20, 2020. The individuals were in their preliminary stage of disease and required no intensive care or oxygen supplementation or intubation.
Patients were either treated with IFN-α2b, arbidol (ARB), which is a broad-spectrum antiviral, or a combination of IFN-α2b plus ARB, and viral clearance was defined as two consecutive negative tests for virus at least 24 hours apart, from throat swab samples.
The researchers found treatment with IFN-α2b, whether alone or in combination with ARB, accelerated viral clearance when compared to ARB treatment alone. IFN treatment was able to significantly reduce circulating levels of IL-6 and CRP, whether alone or in combination with ARB. Noticeably, age and sex did not negate the effects of IFN treatment on viral clearance times or on the reduction in the inflammatory proteins IL-6 and CRP, they said.
Clinical trial next
Despite the study being a small and non-randomised cohort, the work provides new insights into COVID-19 disease, notably accelerated viral clearance from the upper respiratory tract and reduced circulating inflammatory biomarkers, hinting at functional connections between viral infection and host end organ damage by limiting the subsequent inflammatory response in the lungs of patients.
In defense of the treatment method, Fish argues, “Rather then developing a virus-specific antiviral for each new virus outbreak, I would argue that we should consider interferons as the ‘first responders’ in terms of treatment. Interferons have been approved for clinical use for many years, so the strategy would be to ‘repurpose’ them for severe acute virus infections.”
Fish says a randomized clinical trial is a crucial next step but for now, the current findings suggest therapeutic efficacy of IFN-α2b as an available antiviral intervention for COVID-19, which may also benefit public health measures by shortening the duration of viral clearance and therefore slowing the tide of the pandemic.