In addition, to evaluate whether the virulence observed in vivo correlates with viral replication, groups of six-to-seven-week-old female IFNAR−/− A129 mice (n = 6) were inoculated with 102 to 104 FFU of rZIKV-RGN NS2A A117V or rZIKV-RGN and viremia was determined at 2 and 4 days post-infection (Fig. 5D). Here, IFNAR1 is linked to infection.