The original antibody was isolated from donor CC5, a CCHFV survivor, circulating anti-GP38 antibodies were isolated from plasma using affinity chromatography. The paired heavy and light chain sequences were obtained from proteomics and genomics analyses, and the antibody was produced by transfecting Expi293 cells (expiCHO-S cells) with 1:1 ratio of heavy chain plasmid to light chain plasmid.