Evaluation of the Anti-Viral Activity of Human Recombinant Interferon Lambda-1 against SARS-CoV-2

The antiviral activity of recombinant human IFN-lambda type 1 (IFNλ-1) against culture strain of SARS-CoV-2 virus was determined by infecting a highly sensitive VeroE6 coronavirus cell culture after preincubation test (the cell monolayer was incubated with 4-fold dilutions of IFNλ-1 in a concentration range of 0.16-42,500 ng/ml in a culture medium for 12 h at 37°C) and without preincubation (simultaneous addition of different concentrations of IFNλ-1 and SARS-CoV-2 infection in a dose of 102 TCID50). The created recombinant human IFNλ-1 demonstrated obvious antiviral activity against SARS-CoV-2 virus in vitro. In the tests with and without preincubation, IFNλ-1 exhibited significant activity, although somewhat lower in variant with simultaneous addition of IFNλ-1 and virus to the cell culture. It should be noted that the antiviral effect of IFNλ-1 was observed in a wide range of concentrations.