Use of fetal tissue in vaccine development

The use of fetal tissue in vaccine development is the practice of researching, developing, and producing vaccines through growing viruses in cultured (laboratory-grown) human fetal cells.[1] Since the cell strains in use originate from abortions,[2] there has been opposition to the practice and the resulting vaccines on religious and moral grounds.[1][3][4]

Vaccine experts and manufacturers state that vaccines do not contain any of the original fetal tissue or cells, that the abortions occurred decades ago and replenishment with new tissue has not occurred.[5] Although the vaccines are purified from cell debris, traces of human DNA fragments inevitably remain.[6][7][8]

The Catholic Church has encouraged its members to use alternative vaccines, produced without human cell lines, if possible. However, in cases where the public health risks of refusing vaccination may outweigh "the legitimate concern about the origins of the vaccine", believers are "morally free to use the vaccine regardless of its historical association with abortion".[1][3]


Immortalised cell lines are an important research tool offering a stable medium for experiments. These are derived either from tumors, which have developed resistance to senescence, or, in a few cases, from stem cells taken from aborted fetuses.[9] Fetal cell lines have been used in the manufacture of vaccines since 1930s.[10] One of the first medical applications of fetal tissues was their use in the production of the first polio vaccines.[10] For example, in the 1950s, scientists at the Karolinska Institute in Sweden propagated a polio virus in fetal cells to make into a polio vaccine. The resulting vaccine was given to about 2,000 children.[11]

Many other vaccines, including those for chicken pox and rubella, are made using fetal tissue from two pregnancies terminated in the 1960s, for reasons unrelated to vaccine development.[10][12][13] Descendants of the fibroblast cells from these fetuses have been growing in labs ever since, as the WI-38 and MRC-5 cell lines. They are still used to grow vaccine viruses today.[14][1] As of March 2017, at least 300 million vaccines have been given that were made using the WI-38 line alone.[15]


Vaccines that have been or are made using cell lines derived from fetal tissue include:

Of these, the vaccines approved for use in the United States include some of those against rabies (Imovax), rubella, chicken pox, shingles, and adenovirus (as of January 2017).[11]


One historical cell line used in rubella vaccines was obtained from a fetus aborted due to infection with rubella.[18] Rubella during pregnancy can lead to miscarriage (spontaneous abortion), and if it does not, there is a risk of severe disability due to congenital rubella syndrome.[19] By one estimate, rubella vaccination may prevent up to 5,000 miscarriages per year in the United States.[5]


Several of the vaccines in use or advanced development for COVID-19 use the cell lines HEK-293 or PER.C6 for production. In other cases, notably the vaccines made by Pfizer and Moderna, HEK-293 was used during the testing phase.[20]


COS-1 cells are of monkey origin and there are xenogeneic differences between monkey and human proteins.[21]

Position of the Catholic ChurchEdit

The Catholic Church is opposed to abortion. Nevertheless, the Pontifical Academy for Life, concluded in 2005 that parents may allow their children to receive vaccines made from fetal tissue if no alternative exists and there is a grave health risk. Consumers were urged to "oppose by all means (in writing, through the various associations, mass media, etc.) the vaccines which do not yet have morally acceptable alternatives, creating pressure so that alternative vaccines are prepared, which are not connected with the abortion of a human foetus".[3] This Academy also called for the development of new vaccines that can be made by other means.[12]


  1. ^ a b c d "Human Cell Strains in Vaccine Development". History of Vaccines. Retrieved January 5, 2021.
  2. ^ Wadman, Meredith. "Abortion opponents protest COVID-19 vaccines' use of fetal cells". Science. Retrieved January 5, 2021.
  3. ^ a b c "Moral Reflections on Vaccines Prepared From Cells Derived From Aborted Human Foetuses". Pontifical Academy for Life. June 9, 2005. Retrieved January 5, 2021 – via Immunization Action Coalition.
  4. ^ Offit, Paul A. (April 3, 2012). Deadly Choices: How the Anti-Vaccine Movement Threatens Us All. p. 122. ISBN 978-0465029624.
  5. ^ a b "Vaccine Ingredients – Fetal Tissues". Children's Hospital of Philadelphia. July 13, 2020. Retrieved December 8, 2020.
  6. ^ "Vaccines and Related Biological Products Advisory Committee, 154th Meeting". FDA. Food and Drug Administration. November 8, 2018. p. 33–46. Retrieved December 8, 2020.
  7. ^ Neporent, Liz (February 2, 2015). "What Aborted Fetuses Have to Do With Vaccines". ABC News. Retrieved December 8, 2020.
  8. ^ "Vaccine Ingredients — DNA". Children's Hospital of Philadelphia. Retrieved December 8, 2020.
  9. ^ Irfan Maqsood, M.; Matin, M. M.; Bahrami, A. R.; Ghasroldasht, M. M. (2013). "Immortality of cell lines: Challenges and advantages of establishment". Cell Biology International. 37 (10): 1038–45. doi:10.1002/cbin.10137. PMID 23723166. S2CID 14777249.
  10. ^ a b c Storrs, Carina (July 17, 2015). "How exactly fetal tissue is used for medicine". CNN. Retrieved January 26, 2018.
  11. ^ a b c d Wadman, Meredith (January 5, 2017). "Fact-checking Congress's fetal tissue report". Science. Retrieved January 26, 2018.
  12. ^ a b Charo, R. Alta (August 12, 2015). "Fetal Tissue Fallout". New England Journal of Medicine. 373 (10): 890–891. doi:10.1056/nejmp1510279. PMID 26267448. S2CID 205112031.
  13. ^ "Vaccine ingredients". Retrieved February 5, 2019.
  14. ^ "Vaccine Ingredients – Fetal Tissues". The Children's Hospital of Philadelphia. November 6, 2014. Retrieved January 26, 2018.
  15. ^ Wadman, Meredith (March 2, 2017). "Henrietta Lacks Wasn't the Only Woman Who Unknowingly Contributed to Medical History". Slate. Retrieved January 26, 2018.
  16. ^ a b c d Wadman, Meredith (June 27, 2013). "Medical research: Cell division". Nature. 498 (7455): 422–426. Bibcode:2013Natur.498..422W. doi:10.1038/498422a. PMID 23803825.
  17. ^ Binkley, Collin (August 11, 2015). "Scientists say fetal tissue remains essential for vaccines and developing treatments". PBS NewsHour. Retrieved January 26, 2018.
  18. ^ "Animal derived products and National Immunisation Schedule vaccines - updated August 2017" (PDF). Immunisation Advisory Centre. September 19, 2016. Retrieved December 8, 2020.
  19. ^ "Rubella (German Measles)". February 5, 2019. Retrieved February 5, 2019.
  20. ^ Couronne, Ivan (October 20, 2020). "How fetal cells from the 1970s power medical innovation today". Medical Xpress. Retrieved January 5, 2021.
  21. ^ McKenna, Kyle Christopher (2018). "Use of Aborted Fetal Tissue in Vaccines and Medical Research Obscures the Value of All Human Life". The Linacre Quarterly. 85 (1): 13–17. doi:10.1177/0024363918761715. PMC 6027112. PMID 29970932.