Notes on COVID-19 Vaccines and the moral implications of their manufacture

Dr John Kleinsman – Director - Nathaniel Center for Bioethics
Rev Dr Graham O’Brien – Co-chair - InterChurch Bioethics Council
February 2021


Given the global roll-out of vaccination against Covid-19, some have raised concerns about the production of these vaccines – in particular the use of morally compromised human cell lines originally derived from tissue sourced from an aborted foetus. Some people feel caught in a moral dilemma – wanting to do the right thing to protect themselves and others from the deadly COVID-19 virus but unwilling to be morally complicit in the abortion process.

Two of the compromised cell lines in question are HEK 293 (derived in 1973 from kidney issue taken from an aborted foetus) and PER.C6 (developed from retinal cells from an 18-week-old fetus aborted in 1985).

  • The Oxford-AstraZeneca and Johnson & Johnson/Janssen vaccines both use morally compromised cell lines as part of the production process. The University of Oxford website notes that the Oxford-AstraZeneca vaccine uses the HEK 293 cell line and acknowledges that the original cells used to start this cell line were taken from “the kidney of a legally aborted foetus”. ( The Johnson & Johnson/Janssen vaccine is produced using the PER.C6 cell line.
  • For accuracy it needs to be noted that the HEK 293 and PER.C6 cell lines used nowadays are based on “descendants” of the original cells; they are not the cells of the aborted fetus.
  • It is also important to note that these cell lines do not depend on further abortions being performed. This fulfills an important moral criterion for establishing moral justification in situations where a well-intentioned action has unavoidable negative consequences; the chosen action (being vaccinated) will not lead to further immoral outcomes (abortions).
  • In terms of the manufacturing process, it is important to understand that once the vaccines are grown in the cells, the next step is to ‘purify’ the vaccine viruses by removing the cell culture material. Therefore, the final vaccine products contain no live tissue or cellular material from the cell lines on which they were developed or from the original aborted fetus.
  • By contrast, the production of the mRNA vaccines (Moderna and Pfizer) do not require the use of any ethically compromised fetal cell lines.
  • But, while the mRNA vaccines do not use human cell lines in their manufacture, both of these vaccines have had confirmatory tests undertaken using an ethically compromised human cell line (HEK 293). That is why these vaccines are correctly judged to have a ‘link’ to abortion.
  • However, because no cell lines, fetal or otherwise, are required for the ongoing production of the mRNA vaccines, it can be argued that they are, morally speaking, more acceptable than those vaccines which rely on compromised cell lines for their production. For this reason, if the choice is available, and assuming the vaccines are equally effective, those with concerns about the derivation of the cell lines used in vaccine production should choose the mRNA vaccines over the Oxford-AstraZeneca or Janssen vaccines.
  • Nevertheless, when such a choice does not exist, the Roman Catholic Congregation for the Doctrine of the Faith has deemed that, given the current deadly dangers posed by the corona virus, “all vaccinations recognised as clinically safe and effective can be used in good conscience.” This conclusion reflects the fact that the moral link between vaccination and abortion is correctly judged as “remote” for all of the vaccines that are currently available. Put otherwise, the use of any of the vaccines is morally acceptable because “there are differing degrees of responsibility” with respect to the occurrence of the original abortion: “the morally licit use of ... vaccines [linked to compromised cell lines] does not in itself constitute a legitimation, even indirect, of the practice of abortion” for those who had no voice in the decision to procure cells from an aborted fetus. See: .
  • The decision to be vaccinated, whatever vaccine choices are available, is morally indicated – some would say ‘demanded’ – in light of our responsibility to pursue the ‘common good’, understood as our moral duty to protect ourselves and others in society – especially the vulnerable – given the grave danger that exists in the form of an “otherwise uncontainable spread of a serious pathological agent.” (Congregation for the Doctrine of the Faith, 2020)
  • While it would be ideal to have a vaccine with absolutely no association to tissue obtained from an abortion, the alternative to accepting the “remote” association that a vaccine may have to an abortion is to be willing to tolerate, and worse to be knowingly implicated in and have directly contributed to, the deaths of innocent and vulnerable people – deaths that would otherwise have been prevented. For that reason, we argue that a person’s refusal of the COVID-19 vaccine in the current circumstances creates a moral contradiction for anyone concerned about abortion. Why? Because their refusal ultimately undermines the very principle of the inviolable dignity of human life that the person would be drawing on to justify their refusal of the vaccine.
  • Furthermore, those choosing not to be vaccinated would, for their well-being and safety, still be relying on, and therefore benefitting vicariously from, the willingness of the rest of the population to be vaccinated.
  • Some are concerned that the new vaccines have been approved without undergoing the usual safety and efficacy testing procedures. While the development, testing and approval processes have occurred much faster than normal, this has not been done at the expense of the gold-standard testing regimes; all of the approved vaccines have undergone the normal Phase I, Phase II and Phase III ‘double-blind’ studies and the results have been independently verified by experts in the field. “Although no biologically effective medication can ever be regarded as completely safe, the [current] available data indicate that the Pfizer and Moderna vaccines have excellent safety records, and they are in fact far safer than many medications such as aspirin and ibuprofen which are in common use.” See:

In summary, the key points are:

  1. A willingness to be vaccinated against COVID-19 does not imply a moral endorsement of the way they have been produced. While the situation creates a genuine dilemma, it is not a matter of Christians having to overlook the immorality of abortion.
  2. Given the current danger, being vaccinated against the corona virus is accurately described as an act that upholds, and is arguably even demanded by, our duty to the common good of society.
  3. Where a choice exists, it is morally preferable for people to choose either of the mRNA vaccines rather than the Oxford-AstraZeneca or Janssen options.
  4. There have not been any compromises made in testing the safety and effectiveness of the vaccines despite the shortened development and manufacturing time.

Articles of interest:
A link from the Lozier Institute which graphically shows the moral status of the different vaccines is available here: Also see additional link

Vaccine Knowledge Project

How the RNA Vaccine is made:

How the Oxford-AstraZeneca Vaccine is made:
Podcast British Medical Journal

How the vaccine works