Mouse-adapted Influenza B Virus for in Vitro and in Vivo Assessment of Therapeutic and Preventive Efficacy of Antiviral Drugs

Objective: to develop a new antigenic relevance influenza B virus suitable for modeling influenza infection in mice to assess of in vivo and in vitro therapeutic and preventive efficacy of antiviral drugs.Materials and methods: was carried out an adaptation of influenza B virus in BALB/c mice. Was performed, comparative assessment of in vivo and in vitro pathogenicity of the parenta! virus and. adapted, influenza B virus. Was assessed, inhibition of neuraminidase with antiviral drugs (oseltamivir ethoxyacrylate and. Tamiflu) in relation to the adapted, influenza B virus.Results: adapted influenza B virus (B/Novosibirsk/40/2017-MA strain) models non-lethal influenza infection with pronounced, clinical signs of the disease in experimental animals. Were described the destructive changes in lungs and. brain that increases during infection. Analysis of internal organs (lungs, brain, liver, heart, kidneys, spleen) were revealed viral load only in the lungs. Were evaluated, in vivo and in vitro efficacy of antiviral drugs (oseltamivir ethoxysuccinate and Tamiflu®) on the model of influenza infection. Were proved, the high, efficiency of the innovative drug — oseltamivir ethoxysuccinate.Conclusion: the antigen-relevant adapted, influenza B virus (B/Novosibirsk/40/2017-MA strain) can be used, to assess the drug effectiveness against influenza, as well as an additional tool for predicting the effectiveness of the vaccine against drifting strains.