Were fetal cells used to manufacture the mRNA vaccines?
No, neither the Pfizer-BioNTech nor Moderna COVID-19 vaccine utilize fetal cell lines in the manufacturing process for either of these vaccines and are listed as ethically uncontroversial by the Charlotte Lozier Institute, a prominent pro-life organization.
Fetal cell lines are commonly used in research and were obtained from aborted fetuses in the 1970s and 1980s. In all cases, no new fetal tissue is required to utilize any of these cell lines. In the early phases of vaccine development (preclinical testing in animals) both Pfizer-BioNTech and Moderna used one fetal cell line called HEK293 that originated from fetal kidney cells in the 1970s. Use of these fetal cell lines never requires harvesting of new fetal tissue.
Some vaccines in development for COVID-19 do utilize fetal cells lines for manufacturing and development and there are several resources available to help you address ethical concerns. A list of COVID vaccines in development and details regarding the use of fetal cell lines can be found: here