Vaccines – An Aid to Forming Conscience

Bishop Kevin Doran, Chair of the Council for Life, outlines the teaching of the Catholic Church and Vaccines. This article was published in The Furrow, March 2021.  

Vaccination – An Act of Solidarity DOWNLOAD ARTICLE IN PDF

It seems like a lifetime since we first became aware of COVID-19. In the early days of the pandemic, there was some talk about the possibility of a vaccine, but it all seemed very remote. Now, less than a year later, there are no less than thirty-eight different candidate vaccines at various stages of development, and at least five of those are already being used in various jurisdictions. The focus has shifted from “when?” to “what?” and “how?”

The availability of a vaccine which is safe, effective, and widely available represents the best chance of a return to normal living, for all of us, but especially for older people and those with serious underlying conditions. Alongside the technical and scientific questions, ethical concerns have also been raised in some quarters about how some of the COVID-19 vaccines have been developed. While these are valid concerns, there are also reasonable and reassuring answers, if we are ready to hear them.

Safe and Effective:

Some people point to previous high-profile scandals associated with the pharmaceutical industry as a reason for concern. On the other hand, thanks to large scale childhood vaccination programmes in the 1960s many serious diseases like TB, German Measles (Rubella) and Polio have almost completely disappeared in Ireland. The development of vaccines and the immunisation of whole populations has been described as “undoubtedly a positive step” when it comes to the prevention of infectious diseases. 1

Before a vaccine is authorised for use in the general population, a series of trials takes place including, as a final stage, the testing of the vaccine on large numbers of volunteers. There are important protocols in place to ensure that people who agree to participate in these trials have given and are capable of giving informed consent.2

There has been an understandable urgency attached to the development of an effective vaccine for COVID-19. Some surprise has been expressed at the unprecedented speed at which vaccines have been developed and approved. This is probably explained by the unprecedented investment of resources and expertise.

Risk management is a matter of proportion. There is a serious moral obligation on pharmaceutical companies to ensure that there are no short-cuts which would expose end-users to disproportionate risks. The validation of every stage of the process is the role of the regulatory authorities. Ultimately, healthcare and biomedical research are built on trust.3 Bad science is not the only thing that undermines trust. We also need to discern very carefully the sources and the reliability of the information that we find on social media, where opinion is so frequently presented as fact.

Development and Production of Vaccines

The Chinese are sometimes blamed, however unfairly, for COVID-19. It is, perhaps, less well-known that the Chinese began exploring vaccines nearly a thousand years ago. Modern immunology discovered the possibility of developing vaccines using the live virus itself. The virus is “attenuated” (or weakened) by being cultured over a number of cycles in such a way that it loses its capacity for causing serious illness, while remaining strong enough to produce an immune reaction. This process requires a living biological “host” in which the virus is grown. Over the years researchers have used cells taken from chicken or duck embryos, from rabbits, hamsters and monkeys. Since the middle of the twentieth century, many vaccines, including some of those most commonly used to prevent childhood diseases were developed and produced using human foetal cell-lines as the “host”. These cell-lines were developed using biological tissue taken from specific identifiable foetuses aborted in the 1960’s. 4 This has, understandably, raised serious moral concerns and conscientious objections because of the ethical conflict between vaccination (which is about protecting life) and abortion (which is about destroying life).

Many vaccines today use cell lines developed either from ethically sourced human cells (such as umbilical cord blood) or from animal cells (such as Vero monkey cells). The majority of the candidate vaccines for COVID-19 do not depend for their design, development or production on the use of human foetal cell-lines. 5

For many years, scientists have been exploring an approach to the production of vaccines using messenger RNA (or mRNA). Instead of weakened strains of the virus itself, this cutting-edge technology uses chemically produced mRNA, which mimics the action of the virus and trains the immune system to respond. The Pfizer BioNTech vaccine and the Moderna vaccine, which are among the first COVID-19 vaccines to be approved, use this new technology. Human foetal cell-lines were not used in the design, development or production of either of these vaccines, though it is acknowledged that they made use of a foetal cell-line for one of the confirmatory lab tests.

The Church and the Ethics of Vaccination

In 2003, long before anyone heard of COVID-19, Debra L. Vinnedge, wrote to Cardinal Ratzinger, then Prefect of the Congregation for the Doctrine of the Faith (CDF), asking for guidance on whether or not it was lawful to vaccinate children with vaccines prepared using foetal cell-lines. The answer came in the form of an eight page document prepared by the Pontifical Academy for Life and authorised by the CDF. 6 In December 2020, the CDF published a doctrinal Note in which the principles of the earlier teaching were applied to the specific circumstances of the COVID-19 pandemic. 7

St Thomas Aquinas explained that the morality of any action depends primarily on its object (what is being done) and on its end (why it is being done). The circumstances can also undermine the goodness of an act (e.g., playing a trumpet, however well, in the middle of the night).8 When it comes to making a moral assessment of vaccines which depend on foetal cell-lines, there is not just one action involved. We need to ask ourselves what is being done at each stage of the process.

Abortion is the taking of an innocent human life and is, therefore, objectively immoral. Foetal cell-lines are derived from the tissue of an aborted foetus and cultured over many years in laboratory conditions. By the time they are used as a biological host to develop a vaccine, none of the original cells remain, but there is still a material or biological connection with the original act of abortion.

The Church has always made a distinction between formal (deliberate) involvement in an immoral act (which involves sharing the immoral intention of the original act) and material involvement (which may often be incidental and remote). It is not enough for a researcher to say “that he does not approve of the injustice perpetrated by others, but at the same time accepts for his own work the ‘biological material’ which the others have obtained by means of that injustice”.9 There are, however, “differing degrees of responsibility” and the responsibility of those who decide to use foetal cell-lines “is not the same as that of those who have no voice in such a decision”.10

The primary moral concern today is that our present choices would contribute to the shaping of future biomedical research and development. By expressing a principled preference for “ethically irreproachable” vaccines, we make it clear that we do not want biomedical research in the future to depend on abortion or destructive research on human embryos. For that reason, the Church encourages producers of vaccines and health authorities, even those which continue to use human foetal cell lines, to make it clear that they reject the act of abortion and “to produce, approve, distribute and offer ethically acceptable vaccines that do not create problems of conscience for either health care providers or the people to be vaccinated”.11

Vaccination as Moral Act

We can now go on to consider the action of giving and receiving a vaccine which depends on foetal cell-lines. The essential point is not just that the foetal cell-lines are materially remote from the original abortion, but also that the act of vaccination is an intentionally distinct act.

The intention (or end) of the external act, as St Thomas explains, is the object of the internal act of the will.12 The physical (external) act of vaccination and the associated decision (act of the will), are both directed towards a “good end”, namely the protection of life and health, which serves both the good of the individual and the common good. There are also “good secondary ends”, since the management of the pandemic allows people to get back to work and reduces the burden on the economy, thereby allowing resources to be directed back to housing, education, healthcare and the other things that support normal life.

Unless the external act is objectively evil, the morality of the act derives primarily from the will. Vaccination is not, of its nature, evil. As long as the person taking the vaccine does not will (or agree with) the previous abortion, he or she is free from any moral responsibility in relation to it.

It is reasonably argued that the appearance may be given of justifying abortion. This would be an unintended side effect and the Principle of Double Effect applies. Nonetheless, to mitigate the unintended effect, the Church asks people, where possible, to choose a vaccine that is free of any material link to previous abortion and, where that is not possible, to advocate for the production of vaccines which do not have that connection.

Finally, we come to the circumstances, and this is where the most recent Note from the CDF is particularly helpful. 13 One of the circumstances is “the grave danger posed by the COVID-19 pandemic”. The CDF also recognises that various factors may make it impossible for doctors and their patients to actually choose a vaccine that is “ethically irreproachable”. The successful development of a safe and effective vaccine is just the first step. Other factors which may affect availability include transportation, storage, distribution and cost. Ultimately it depends on the decisions of individual governments to license and purchase such vaccines. 14

For all of these reasons, the CDF Note states: “It must therefore be considered that, in such a case, all vaccinations recognized as clinically safe and effective can be used in good conscience”. 15 This “does not constitute formal cooperation with the abortion from which the cells used in production of the vaccines derive.” Catholics, while choosing where possible “ethically irreproachable” vaccines, may use any COVID-19 vaccine that is approved for clinical use, on the understanding that they themselves do not approve of or consent to abortion for the purposes of biomedical research.

A Question of Conscience:

Everyone is obliged to follow his or her well informed conscience. In the context of a global pandemic, it is important to consider that vaccination is not simply a private matter. This reality must inform any judgement of conscience. The CDF Note stops short of describing vaccination as a moral obligation. It does say, however, that:

“Those who, however, for reasons of conscience, refuse vaccines produced with cell lines from aborted foetuses, must do their utmost to avoid, by other prophylactic means and appropriate behaviour, becoming vehicles for the transmission of the infectious agent. In particular, they must avoid any risk to the health of those who cannot be vaccinated for medical or other reasons, and who are the most vulnerable”. 16

The Distribution of Vaccines

The costs of developing a vaccine are significant but the potential rewards are even greater. It is reasonable that pharmaceutical companies would wish to protect their “intellectual property” investment. How is this to be balanced with the urgent need of populations which cannot afford the cost? At time of writing, it is being reported that the vaccine developed by Astra-Zeneca and Oxford University is to be made available on a not-for-profit basis, which is highly commendable from an ethical point of view.

Catholic Social Teaching, while in no way denying the importance of the free market for the common good, requires that essential medical treatment should be made available on the basis of need, not on the basis of the capacity to pay. The ownership of private property carries with it “a social mortgage”.17 Under the principle of the Universal Destination of Goods, there is an ethical responsibility on pharmaceutical companies to moderate their desire for profit. Likewise, there is an ethical responsibility on governments, under the principle of distributive justice, to ensure that, both in their own societies and in the wider world, those who are most at risk are the first to receive the vaccine. Pope Francis says:

“The preferential option for the poor, this ethical-social need that comes from God’s love, inspires us to conceive of and design an economy where people, and especially the poorest, are at the centre. And it also encourages us to plan the treatment of viruses by prioritising those who are most in need. 18

The TRIPS agreement is an annexe to the agreement which established the World Trade Organisation. 19 It recognises the right of WTO members “to protect public health and, in particular, to promote access to medicines for all”. 20 It allows governments to provide for the production of generic versions of essential medicines not only for the domestic market but also for countries facing public health problems and lacking the capacity to produce generic drugs. Given the significant capacity of the pharmaceutical industry in Ireland, it should be considered whether we might have a contribution to make in producing vaccines, under license, as a service to developing countries.


1              Pontifical Council for Pastoral Assistance to Healthcare Workers. New Charter for Healthcare Workers. Philadelphia, NCBC, 2017, #69

2             WMA. Declaration of Helsinki, 1964 (Revised 2013) # 28. See also European Communities (Clinical Trials on Medicinal Products for Human Use) Regulations. Dublin: Stationery Office, 2004

3              D. O’Mathuna, “Trust and Clinical Research”, Research Practitioner, 10.5, September–October 2009, 170–177

4              Cf. Olshansky, and Hayflick. “The Role of the WI-38 Cell Strain in Saving Lives and Reducing Morbidity” AIMS Public Health 2017 Vol 4 127-38; cf. also College of Physicians of Philadelphia: “Human Cell Strains in Vaccine Development”, 2018 from cell-strains-vaccine-development. Sourced on 3rd Dec 2020

5              Cf. J.L Sherley and D. Prentice. “An Ethics Assessment of COVID-19 Vaccine Programs”, from Sourced on 19th Nov. 2020

6             Pontifical Academy for Life. “Moral Reflections On Vaccines Prepared From Cells Derived From Aborted
Human Foetuses”. Rome, 2005. Also Dignitas Personae. Rome 2008, #34-35.

7              CDF. Note on the morality of using some anti-Covid-19 vaccines. Rome: 21st Dec. 2020. (Hereinafter “Note”) This note confirms the guidance given by the Irish Bishops in Welcoming Vaccines for the Common Good, 10th Dec. 2020.

8              Thomas Aquinas. Summa Theologiae Ia IIae, Question 18. Cf also Pope John Paul II, Veritatis Splendor. Rome, 1993 #71-83

9              Dignitas Personae, #35. See also “Note” #1

10             Ibid.

11             CDF “Note”, #4

12             Summa Theologiae I, II, 20 & 21

13             CDF “Note”, #3

14             Ibid., #2

15             Ibid., #3

16             Ibid., #5

17             Pope John Paul II, Solicitudo Rei Socialis, Rome: Libreria Editrice Vaticana. 1987, #42

18             Pope Francis. General Audience, 19th August 2020

19             World Trade Organisation. TRIPS Factsheet. Accessed on 3rd Sept 2020

20             World Trade Organisation. “Declaration On The Trips Agreement And Public Health”. Ministerial Conference Fourth Session, Doha, 9 – 14 November 2001