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Response to "Animals Containing Human Material" (2010)

David Albert Jones responds on 7 September 2010 to "Animals Containing Human Material", a consultation paper from The Academy of Medical Sciences.


The Anscombe Bioethics Centre in Oxford is the oldest national bioethics centre in the United Kingdom, established in 1977 by the Roman Catholic Archbishops of England and Wales. It was previously known as The Linacre Centre for Healthcare Ethics and was situated in London before moving to Oxford. The Centre engages with the moral questions arising in clinical practice and biomedical research. It brings to bear on those questions principles of natural law, virtue ethics, and the teaching of the Catholic Church, and seeks to develop the implications of that teaching for emerging fields of practice. The Centre engages in scholarly dialogue with academics and practitioners of other traditions. It contributes to public policy debates as well as to debates and consultations within the Church.

The Centre welcomes the opportunity to respond to the Academy of Medical Sciences consultation on Animals Containing Human Material, recognizing that this covers important ethical issues of wide concern. This response generally does not rely on premises held by Catholics only, except where this is explicitly stated. Furthermore, much of this response goes beyond the current teaching of the Church, both because it concerns scientific questions outside the Church's competence (for example, the scientific definitions of various ways human material may be contained by animals), and because this is an area in which Church teaching is still in the process of formation.

Scope of the working group

However the working group has decided, to avoid replication of previous work and debates, not to consider:

a. Scientific or ethical issues relating to the general use of animals in research.

b. The use of human admixed embryos in research (and other issues addressed in the debates of the Human Fertilisation and Embryology Act (2008)).

c. Broader issues relating to the genetic modification of animals or plants (e.g. the genetic modification of plants or animals for agricultural purposes).

It is prudent for the working group to seek not to replicate previous work, and to focus on the specific scientific and ethical issues of research involving non-human animals containing human material. Nevertheless, to avoid the three above-mentioned areas altogether would be difficult to achieve and, even if it could be achieved, would be detrimental to the study, for the following six reasons:

1) Reflection on the area studied will sometimes be by way of contrast (for example, the contrast between a non-human animal containing human material and a human animal containing non-human material).

2) Not only is the contrast helpful for ethical reflection but the identification of the boundary of this area depends on its relationship to other areas (for example, the distinction between a non-human embryo containing human material and a human embryo containing non-human material, i.e. a human admixed embryo).

3) Considerations of the general issues (of for example the use of animals in research) seem a necessary prerequisite to identifying the considerations that obtain in this specific kind of research.

4) The final report would be misleading if it gave the impression that the only important ethical considerations for this area are those that are unique to it. On the contrary generic considerations of ethical research will be relevant to this area as to other areas.

6) In general, considerations of a specific example may illuminate the more general ethical question so that one might wish to revise previous generic judgements. Hence it may be, for example, that reflection on the use of animals containing human material might also shed light on the general issue of genetic modification of animals.

Thus, while this submission will focus on research on non-human animals containing human material it will occasionally give consideration to broader issues (including a to c above) and would recommend that the working group also gives consideration to such broader issues when these are relevant.

The contrast with modifying human beings

To understand the ethical issues involved in modifying nonhuman animals with human material it is useful to consider the modification of human beings with material from non-human animals.


The ethical distinctions made by Pius XII were reiterated by John Paul II in 2000:

'(I)n 1956 Pope Pius XII raised the question [of the legitimacy of xenografts]. He did so when commenting on the scientific possibility, then being presaged, of transplanting animal corneas to humans. His response is still enlightening for us today: in principle, he stated, for a xenotransplant to be licit, the transplanted organ must not impair the integrity of the psychological or genetic identity of the person receiving it; and there must also be a proven biological possibility that the transplant will be successful and will not expose the recipient to inordinate risk.' 2

The types of transplantation that prima facie pose a threat to human identity are the transplantation of neurological tissue and the transplantation of reproductive tissue 3 4 A more recent document also deals explicitly with the attempt to create cytoplasmic hybrid embryos:

'From the ethical standpoint, such procedures represent an offense against the dignity of human beings on account of the admixture of human and animal genetic elements capable of disrupting the specific identity of man. The possible use of the stem cells, taken from these embryos, may also involve additional health risks, as yet unknown, due to the presence of animal genetic material in their cytoplasm. To consciously expose a human being to such risks is morally and ethically unacceptable.' 5

6 7

Implications for use of animals containing human material

If an intervention is morally acceptable in principle on a human being then, a fortiori, it is acceptable in principle on a non-human animal (abstracting from the issue of environmental impact where the modification of a non-human organism might have a much great impact than the modification of a human being). If at least some limited use of xenografts in human patients (such as heart valves or corneas) is acceptable in principle, then the use of human material in animals should also be accepted in principle. Furthermore, if the use of animals in research is acceptable in principle (this is a matter of dispute, but the mainstream Catholic moral tradition is firmly in favour of the use of non-human animals for human benefit, including their use in scientific research) then the introduction of human material into research animals is also acceptable in principle. The same concerns (animal welfare, proper scientific rationale, lack of ethically preferable alternative means) that pertain to animal experimentation in general pertain to experimentation using human material.

Unacceptable uses of human material in non-human animals

The principles identified by Pius XII in 1956 in relation to xenotransplantation also help identify unacceptable uses of human material in non-human animals:

'The key point is that the combination should not be such as to lead to perplexity about the identity or moral status of the animal. This raises acute questions about the transfer of significant amounts of human neurological tissue into a closely related non-human animal. Experiments reported in the late 1990s showed that transfer of neurological tissue from developing quails to developing chickens could have an effect on the behaviour of the mature birds. 8 Such transfer of psychological characteristics between a human being and a chimpanzee, for example, would cause perplexity about the moral status of the creature produced. This would be unfair to the being created and would be offensive to the specific dignity of human beings. The working group should consider how to identify and prohibit any and all interventions that could transfer human psychological traits to a non-human animal.'

It should also be emphasised that any human material used in this way must itself have been derived ethically. This means that no human beings were unjustly harmed for the sake of obtaining their tissue (for example, human embryos destroyed for their cells) and that human beings unjustly harmed outside a medical context (for example, foetuses who are aborted or Chinese political prisoners who are executed) are not then exploited for their tissue. Material for controversial scientific experimentation (and the mixing of human material with non-human is archetypal of a controversial use) should in any case not be taken from those who have not given specific and fully-informed consent.

Charting the boundary

In arguing for a prohibition on the transfer of human psychological traits to non-human animals I am not excluding all transfer of human neurological tissue. It seems highly unlikely that the transfer of very few neurones, or the transfer of neurones to the peripheral nervous system, could facilitate a transfer of psychological traits. There will be an area of uncertainty here and reason for caution, but there will also be clearly acceptable and clearly unacceptable examples. It may be that a useful way forward is to forbid the clearly unacceptable and establish some means of distinguishing (for example by ethical review) where the acceptability is in doubt.

In the case of reproductive tissue it is the confusion of reproductive functioning that is the problematic area. Hence transfer of germ cells need not cause a problem if this does not lead to gametogenesis or to fertilisation but, for example, is simply for the purpose of testing an immune reaction. Similarly the transfer of human stem cells into a non-human animal does not cause an inherent ethical problem if they do not actually produce neurological or reproductive tissue (even though these cells would have the potential, in principle, to produce such tissue). This assumes of course that the stem cells were generated in an ethical manner (for example by inducing pluripotency in somatic cells from a competent adult after informed consent).

In relation to the transfer of human genes to non-human animals it is very difficult to know where to draw the line. Tonti-Filippini and others have produced a strong argument against allowing any transfer of human genes to animals. 9

Safety and environmental considerations

There has long been a concern within the environmental movement that genetic modification in agriculture is dangerous because of the possibility of cross fertilisation. While such critics have not been able to establish any clear health risk in consuming genetically modified agricultural products, the problem of containment is a legitimate concern. When combined with the potential medical danger to human beings posed by introducing human genes into non-human animals, the issue of containment is crucial. This is a significant biohazard and for this reason should be limited to contexts where the risks can be minimised, that is, laboratory conditions and not the natural environment.

Justification, benefit, and moral pluralism

These issues are subtle and it is difficult to get consensus on how to identify what is acceptable and what is unacceptable in this area. It is possible to take a more inclusive view of what comprises psychological traits, reproductive functioning or genetic identity. On this view doubtful cases should be prohibited. On the other hand it is possible to take a narrower view, restricting what is prohibited to what everyone agrees is unacceptable.

In a morally pluralistic society there are various options for working with these different views. One approach is to permit activity unless it clearly contravenes agreed norms (bearing in mind that industry, as well as interest groups, may be trying hard to influence those norms). This approach may be described as libertarian and it has a clear resonance with elements of modern political culture. Whatever the merits of this approach as regards deregulation in research, it does not justify the use of communal resources to fund research. An example of just such a libertarian approach can be seen in the United States where research may be legal but may still be excluded from federal funding. This division is unusual in the United Kingdom and shows the limitations of libertarianism to resolve differences in public policy.

Even the Catholic theological tradition, which is highly self-reflective, explicit and articulate in the expression of its moral judgements (whether or not one agrees with those judgments) is hesitant in the area of the combination of human and animal material. It is a subtle and novel area and not one in which it is easy to distinguish the acceptable from the unacceptable. It would seem wise, therefore, for the working group also to acknowledge this and to be modest in its goals and tentative in its conclusions.

This submission has attempted to identify some unacceptable cases, some acceptable cases, and some principles that are relevant to identifying the unacceptable. While proposing these examples and principles, this submission also proposes this general method:
  • identify some ethically acceptable examples

  • identify some ethically unacceptable examples

  • clarify the principles used to identify unacceptable examples

  • recommend limits (prohibitions) which might be set out in legislation or regulation

  • recommend some mechanism for resolving doubtful cases in the future (such as a national ethics body that would be able to attract widespread respect)
Finally, it should be reiterated that while there has been discussion on this issue among Catholic theologians, and even by Popes, much of this discussion is of a tentative character. To the extent that this is the case, this submission cannot claim to represent the Catholic view of the matter. It is rather offered as a contribution to a discussion that is ongoing within the Church as it is within society at large.


1. Address to the Italian Association of Cornea Donors and to Clinical Oculists and Legal Medical Practitioners, 14 May 1956.

2. Address of the Holy Father John Paul II to the 18th International Congress of the Transplantation Society , Tuesday 29 August 2000.

3. The Charter for Health Care Workers (1995), n. 88.

4. Donum vitae, Congregation for the Doctrine of the Faith, 22 February 1987, I, 6.

5. Digntias Personnae, Congregation for the Doctrine of the Faith, 8 September 2008, para. 33.

6. Prospects for Xenotransplantation: Scientific Aspects and Ethical Consideration, 26 September 2001 Pontifical Academy for Life, para. 15.

National Catholic Bioethics Quarterly Winter 2006: 698.

Proc. Natl. Acad. Sci. U.S.A. 94 (5): 2001-2006. Rick Weiss, Of mice, men and in-between: Scientists debate blending of human, animal forms, Washington Post, 20 November 2004.

National Catholic Bioethics Quarterly Winter 2006: 689-704.