In the last few decades, laboratory and therapeutic applications of cell culture-derived biologicals have expanded from their use in diagnostic and research fields to the prevention and treatment of infectious diseases, certain forms of cancer, immunological and congenital conditions, and cell and gene therapy. While significant therapeutic benefits obtained from the use of cell culture-derived biologics (e.g., recombinant proteins, monoclonal antibodies [mAb], and vaccines) are unequivocal, the complexities associated with the manufacture of such products is acknowledged. Primary and continuous cell lines used in the manufacture can be associated with risk of contamination with endogenous retroviruses, latent viruses, or new and emerging agents. Some cell lines, such as Chinese hamster ovary (CHO) cells, have an excellent safety record with no documented safety risks…