IFNAR1 and infection: Based on our infection experiments in wild-type weanling C57BL/6J and IFNAR−/− mice, we concluded that of the three chimeric JEV/ZIKVs, rJEV/ZIKVP6-740 was more attenuated than rJEV/ZIKVMR-766 or rJEV/ZIKVPRVABC-59.