"The retinal cells used to make the COVID-19 adenovirus vaccine (J&J/Janssen) were isolated from a terminated fetus in 1985 and adapted for use in growing adenovirus-based vaccines in the late 1990s. Adenovirus-based vaccines that cannot replicate when administered to people need to be produced in cells that have the necessary gene to allow for large quantities of the virus to be made. The retinal cell line, called PER.C6, was adapted to enable production of these altered viruses."