Thus, unlike the Zika BOB previously described using ZKA35 mAb,15 serum antibodies blocking the binding of the F9 mAb are transiently detected in the Zika BOB (within 6 months from the time of infection) and, in line with DENV NS1– and ZIKV NS1–specific IgG3 assays,2,33 may represent an alternative tool to identify recent virus exposure. The gene discussed is IGHG3; the disease is infection.