<i>In vitro</i> antiviral activity of VIFERON® rectal suppositories against SARS-CoV-2

Abstract

In 2020–2021, the world was engulfed by the pandemic of a new coronavirus infection (COVID-19) caused by the SARS-CoV-2 virus. The low population coverage with vaccination against COVID-19 and the lack of herd immunity result in the need to find an effective and safe etiotropic treatment. Medicinal agents for treatment of COVID-19, approved while preparing this publication, have several limitations related to the conditions of their use and/or population category. In this situation, interferon-containing drugs widely used in Russia and the CIS for prevention and treatment of viral infectious diseases, i.e. ARVI and influenza, may hold promise. This study aims to confirm in vitro antiviral activity against SARS-CoV-2 for the preparation VIFERON® containing recombinant human interferon alpha-2b (IFNα-2b). Materials and methods. Vero CCL-81 cells were infected with hCoV-19/StPetersburg-RII3524VR4/2020 strain of SARS-CoV-2 at doses of 10 TCID50 or 100 TCID50 per well. The suppressive effect of IFN-2b, extracted from VIFERON® in dosage form of rectal suppositories, was evaluated by qRT-PCR at 24 h and 48 h after the infection of cells in two schemes, simulating preventive (24 h before infection) and therapeutic (2 h after infection) use of drugs. Results. IFNα-2b at concentrations of 800, 400, 200, 100 and 50 IU/ml, extracted from rectal suppositories of VIFERON®, showed high biological activity, displayed as inhibition of SARS-CoV-2 strain replication in both infectious doses evaluated either at 24 h or at 48 h after cell infection. The “preventive” vs. “therapeutic” scheme was found to be more effective. In the “preventive” scheme the virus titre decreased by more than 3 lg TCID50 at 24 hours post-infection and by 5–6 lg TCID50 at 48 hours post-infection after administration of 800 IU/ml IFNα-2b. Conclusion. The study results evidence that VIFERON® in dosage form of rectal suppositories may be promising for prevention and treatment of new coronavirus infection in clinical practice.