Foreign DNA In Vaccines
In 2010, the FDA issued guidance for industry on the use of immortal cell lines (cells that proliferate forever) in vaccines:
“Some continuous cell lines, including Vero cells and Chinese Hamster Ovary cells, have been used as substrates for licensed biologicals.
Cell lines might have biochemical, biological, and genetic characteristics that differ from primary or diploid cells (e.g., they are typically aneuploid and have accumulated genetic changes).
Because the mechanism by which most cell lines become immortal is generally unknown, and because some cell lines form tumors when inoculated into immunodeficient rodents, there are additional concerns for continuous cell lines … including the potential that transformation was caused by an adventitious agent and potential risks from residual DNA.”