IFNAR1 and Zika virus infectious disease: Mice with defects in the interferon system—single and double knockouts of the type I and type II interferon (IFN) receptors on either the 129/SV genetic background (A129 or AG129, respectively) or single type I knockout on C57BL/6 genetic background (IFNAR1−/−) or wild-type C57BL/6 mice treated with an IFNAR1 receptor blocking monoclonal antibody– are frequently used to study Zika virus infections in adults.