Addressing concerns related to religious beliefs

The Issue

Some COVID-19 vaccine hesitancy stems from deeply held religious beliefs. There are some adherents of faiths opposing abortion (e.g., Roman Catholics) who may be concerned about the use of cell lines of remote fetal origin in vaccine research and development. Muslims and Jews may be concerned that the vaccines contain pork-derived ingredients (pork-derived gelatin is used as a stabilizer in some vaccines).

Sound Bites

  • Fetal cell lines are not the same as fetal tissue. None of the available COVID-19 vaccines contain any tissue from an aborted fetus.
  • The cell lines involved in testing or producing COVID-19 vaccines descend from cells taken from elective abortions in the 1970s and 1980s. These cell lines are maintained to have an indefinite life span. The current cells are thousands of generations removed from the original fetal tissue. None of the available COVID-19 vaccines involve fetal cells taken from recent abortions.
  • Even if cells with remote fetal origins are used to grow some vaccine viruses, the vaccines do not contain these cells or any pieces of DNA recognizable as human DNA.
  • Several faith-based groups have stated that the net good from COVID-19 vaccines outweighs concerns about fetal cell lines.
  • The Vatican’s doctrine office has stated that it is “morally acceptable” for Catholics to receive COVID-19 vaccines that have used cell lines from aborted fetuses in their research and production process. Pope Francis has suggested that getting vaccinated against coronavirus is a “moral obligation.”
  • COVID-19 vaccines contain no objectionable ingredients for people of faith who avoid pork products.

Questions for Exploring Patient Concerns

  • What have you heard about COVID-19 vaccines and [fetal tissue] [pork products]?
  • [For concerns related to fetal tissue] Are you aware of the differences between the mRNA vaccines (e.g., Pfizer-BioNTech, Moderna) and viral vector vaccines (e.g., Johnson & Johnson/Janssen) in relation to this issue?
  • [For concerns related to fetal tissue] What is the greater consideration for you: the remote connection of a COVID-19 vaccine to an aborted fetus or taking the vaccine as an act of charity toward other members of your community?

What We Know

Use of Cell Lines With Remote Fetal Origin. Several common live attenuated vaccines—including rubella, varicella, and hepatitis A vaccines—are made by growing the necessary viruses in fibroblast cells that have a remote fetal origin. The primary strains involved in vaccine production are WI-38, which was derived at the Wistar Institute in Philadelphia, Pennsylvania, and MRC-5, which came from a Medical Research Council laboratory in London, England. Both cell lines were created in the 1960s using lung cells from fetuses aborted legally for reasons not associated with vaccine production.

The COVID-19 vaccines involve other cell lines of fetal origin:

  • HEK-293 is a kidney cell line from a fetus aborted in 1972 in the Netherlands.
  • PER.C6 is a proprietary retinal cell line (owned by Janssen) from a fetus aborted in 1985 in the Netherlands.

The Pfizer-BioNTech and Moderna mRNA vaccines used the HEK-293 cell line for confirmatory testing to demonstrate how a cell could take up mRNA and produce the SARS-CoV-2 spike protein or to characterize the SARS-CoV-2 spike protein. Neither vaccine is produced using fetal cell lines. Notably, the pro-life Charlotte Lozier Institute lists these vaccines as “ethically uncontroversial.”1

The Vatican’s doctrine office (Congregation for the Doctrine of the Faith) has stated that when ethically irreproachable COVID-19 vaccines are not available, “it is morally acceptable to receive COVID-19 vaccines that have used cell lines from aborted fetuses in their research and production process.”2 Additionally, the United States Conference of Catholic Bishops has stated that “in view of the gravity of the current pandemic and the lack of availability of alternative vaccines, the reasons to accept the new COVID-19 vaccines from Pfizer and Moderna are sufficiently serious to justify their use, despite their remote connection to morally compromised cell lines.”3 In a January 2022 speech, Pope Francis suggested that getting vaccinated against the coronavirus was a “moral obligation”—his strongest words to date—and denounced how people had been swayed by “baseless information” to refuse one of the most effective measures to save lives during the pandemic.4

The Johnson & Johnson/Janssen viral vector vaccine uses the PER.C6 cell line for vaccine production. The adenovirus that serves as the vector is rendered replication-deficient by replacing two genes needed for reproduction with the gene for SARS-CoV-2 spike protein. Because viruses need cells to reproduce and the altered virus cannot reproduce, the PER.C6 cell line was modified to include the gene removed from the adenovirus. These modified cell “factories” enable the production of large quantities of virus. Because PER.C6 cells are used in the manufacturing process, the Charlotte Lozier Institute considers the Johnson & Johnson/Janssen vaccine to be “ethically controversial.”1 The United States Conference of Catholic Bishops has stated that the Pfizer-BioNTech or Moderna vaccine should be chosen over the Johnson & Johnson/Janssen vaccine if a choice is possible. If it is not possible to choose which vaccine is administered, then it is “morally acceptable” to accept the Johnson & Johnson/Janssen vaccine.5

Use of Ingredients Derived From Pork. Islamic law includes the concepts of halal (lawful or permitted) and haram (unlawful or prohibited). In reference to food, halal is the dietary standard, as prescribed in the Qur’an (the Muslim scripture). Pork and other pig products are considered to be haram.

Pork-derived gelatin has been used widely as a stabilizer in other vaccines. The possibility that COVID-19 vaccines may contain porcine gelatin has raised concern among Muslims that the vaccines may not be halal.

COVID-19 vaccines do not contain components of porcine origin. Muslims who remain concerned should be aware of the following recommendation from a 1995 seminar held by the Islamic Organization for Medical Sciences in Kuwait: “the gelatin formed as a result of the transformation of the bones, skin, and tendons of a judicially impure animal is pure, and it is judicially permissible to eat.”6

Judaism has similar dietary laws restricting what can be consumed by followers of the faith. Food considered suitable for eating is called kosher; pork is considered non-kosher and should not be consumed. However, several Jewish authorities have stated that there is no problem with porcine or other animal-derived ingredients in non-oral products, including vaccines.7,8


  1. Sherley JL, Prentice DA. An ethics assessment of COVID-19 vaccine programs. On Point Issue 46. Charlotte Lozier Institute. May 6, 2020. Accessed March 24, 2022.
  2. Vatican News. Vatican CDF says use of anti-Covid vaccines “morally acceptable.” December 21, 2020. Accessed March 24, 2022.
  3. Rhoades KC, Naumann JF. Moral considerations regarding the new COVID-19 vaccines. Washington, DC: United States Conference of Catholic Bishops; December 11, 2020. Accessed March 24, 2022.
  4. Winfield N. Pope on COVID vaccines says health care a ‘moral obligation.’ AP News. January 10, 2022. Accessed March 24, 2022.
  5. U.S. Bishop Chairmen for Doctrine and for Pro-Life address the use of the Johnson & Johnson Covid-19 vaccine [press release]. United States Conference of Catholic Bishops; March 2, 2021. Accessed March 24, 2022.
  6. Gezairy HA. Dear Dr [letter]. World Health Organization Regional Office for the Eastern Mediterranean. July 17, 2001. Accessed March 24, 2022.
  7. McGuire R, Crawford N, Lewis G. Porcine gelatin and vaccines. Melbourne Vaccine Education Centre. February 2019. Accessed March 24, 2022.
  8. Public Health England. Vaccines and porcine gelatine. 2020. Accessed March 24, 2022.

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