IFNAR1 and infection: While interferon-α receptor knockout (IFNAR-KO) mice were infected with 1.0 × 106 50% tissue culture infective dose (TCID50) of SFTSV subcutaneously, all mice died within 5–7 days after infection, all the SFTSV-infected IFNAR−KO mice survived when the mice were administered with favipiravir within 3 days post infection [20,21].