ART4 and infection: Approximately 75 million mutagenized HAP1 cells were infected with a recombinant vesicular stomatitis virus (VSV) encoding the glycoprotein of SFTSV (strain HB29, rVSV-SFTSV) in place of VSV G. Challenge of non-mutagenized HAP1 cells with rVSV-SFTSV or mutagenized HAP1 cells with wild-type VSV left no surviving cells 7–10 days post infection.