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COVID-19 vaccines developed with human embryonic cells – Expert Reaction  

Religious leaders and anti-abortion groups have raised concerns over the use of human cells in COVID-19 vaccine development.

Senior Catholic leaders in the United States and Canada, along with other anti-abortion groups, have protested the use of cells derived from electively aborted human fetuses. Yesterday, Anglican Archbishop of Sydney Glenn Davies said he would likely boycott the COVID-19 vaccine being developed by Oxford University, on these ethical grounds.

The SMC asked experts to comment on the use of human embryonic cells in vaccine development. 

Dr Nikki Turner, Director Immunisation Advisory Centre, University of Auckland, comments:

“Human cell lines that are used for the development of some types of vaccine need to be sourced from human material. For the development of vaccines such as the rubella-containing vaccines, and chicken pox and shingles vaccines, the original source of human tissue did come from aborted fetuses.

“What is very important is that the decision to terminate the fetus in these situations was unrelated to the use of the fetal material to enable sourcing of a cell line for a vaccine. Once the human cell is sourced it is then grown in the laboratories and no further sourcing is required.”

No conflict of interest.

Associate Professor Helen Petousis-Harris, Vaccinologist, University of Auckland, comments:

Extended comment available on Sciblogs.

“The vast majority of vaccines do not contain cells, human or otherwise. One exception to this is the BCG vaccine, which is a live bacteria. However, cells (cell lines) are often used during manufacture. Some vaccines necessitate the use of human-derived cell lines.

“Some viruses will only grow in human cells, such as rubella virus. This means that stocks of human cells are needed. The cells must be sterile and free from potential harmful agents. They must also be immortal, able to divide and divide forever. You start with a few cells from the freezer and nurture them until they are billions. In the 1960’s and 70’s some human cell lines were established from fetal cells which are able to divide virtually indefinitely. The cells used now are not the originally harvested cells, they are descendants of those cells. Perpetual human cell lines from the 1960s and 70’s are used to grow several viruses for vaccine use, they are not part of the final formulation. Vaccines do not actually contain cells. Babies are not being aborted in order to produce vaccines.

“While some of the approaches to vaccine manufacture do not require the use of cells of any kind (such as the RNA vaccines), others do. The viral vector vaccines do require the use of cells. The viral vector is a well characterised virus such as an adenovirus that has had a coronavirus gene inserted. The combination goes through its life cycle or is ‘grown’ in cells. These calls can pump out massive amounts of the viral protein (or the viral vector vaccine) that can then be purified and used in the final formulation.

“Many vaccines are grown in non-human cells, such as the HPV and hepatitis B vaccines, which use bakers yeast or an insect cell line. However, when a new virus that affects humans emerges and the scientists are under massive time pressures, using human cell lines is a pragmatic choice. The system needs to look as human as possible to have the best chance of success.

“There are several COVID-19 vaccine approaches in development that use a human cell line to grow the vaccine, and this includes the Oxford/AstraZeneca viral vector vaccine. These cell lines have been used safely and effectively for decades, are well characterised, and licenced for use in the production of human medicines. We cannot avoid these cell lines if we are to have COVID-19 vaccines anytime soon. The nucleic acid vaccines (RNA vaccines) are not made in cell lines at all. But even the RNA vaccines will have benefited from research that utilised human cell lines.

“For more information about animal products and vaccines, including considerations from other religions, see the factsheet from the Immunisation Advisory Centre.”

Conflict of interest statement: Has investigator-led studies funded by industry and has served on industry funded expert advisory boards for GSK, Pfizer, and Merck. She does not receive personal honorarium.

Professor Alan Davidson, Head of Department, Department of Molecular Medicine and Pathology, University of Auckland, comments:

Human embryonic cell lines like HEK293 cells, which was originally derived from a legally aborted foetus in the Netherlands in 1973, are commonly used across the world for research. Indeed, scores of medical breakthroughs would not have been possible without them. The power of these cells lies in the ease with which they grow and how readily they can be manipulated to produce human proteins or viruses. As a result, they are critically important for vaccine development. Many common vaccines, including those used to treat measles, mumps and chickenpox, are made with human embryonic cell lines.

“In the case of some COVID-19 vaccines under development, HEK293 cells are being used. This has re-ignited a long-standing controversy around moral concerns of using cells with a historical association with abortion. While calls for alternative cell lines are being raised, the options are limited. Non-embryonic HeLa cells are a possibility but these have their own ethical problems, having been collected in the 1950’s without informed consent.”

No conflict of interest.

Professor Andrew Shelling, Associate Dean (Research) Faculty of Medical and Health Sciences, University of Auckland, comments:

“Medical research and development of treatments for human disease in laboratories in New Zealand and around the world rely on the use of human cells. Being able to grow human cells in cultures as cell lines has been absolutely vital to our understanding of human disease and has directly led to the development of most modern medicines. Cell lines are the workhorses of laboratories around the world and are a key part of our arsenal to develop new drugs and treatments. Some of these cell lines have been around for over 50 years. Some of the cell lines are obtained from cancer tissue, others are modified from normal tissue.

“The current thrust to develop vaccines against COVID-19 has involved the use of human cell lines. One of the most common cell lines used is called human embryonic kidney 293 cells, also known as HEK 293. It was developed nearly 50 years ago from an aborted foetus. Over the past 50 years, HEK 293 has been used to develop our fundamental understanding of human biology and has been used in the development of many new drugs and treatments including vaccines. In most cases, the cell line is used as a mini-factory to help produce the ingredients needed for the vaccine.

“These historical foetal cell lines are controversial, and raise ethical issues, however it is important to note that society has benefited from their use. In the absence of alternative methods, they still remain the best tools we have. It’s continued use as a key tool in our development of a COVID-19 vaccine is important to all of society.”

Conflict of interest statement: None, I’m a medical researcher in the area of cancer and reproductive genetics.

Gareth Jones, Emeritus Professor of Anatomy, University of Otago, comments:

Objections to the use of vaccines manufactured using cells derived from a small number of human fetuses electively aborted some time in the past surface from time to time. This is not a new phenomenon, neither is the objection a new one.

“In these cases, the abortions were not carried out in order to provide material for production of the vaccines. There is no direct connection between the two. No abortions were performed in order to provide material for the vaccines. The cell lines were created in the 1960s to 1980s, and have been used to manufacture vaccines against a host of conditions including rubella, shingles, and cystic fibrosis. Use of vaccines such as these and many others have been of inestimable medical value, especially but not only for children.

“Some argue that use of cells such as these is unethical because it exploits innocent human beings who were aborted. However, it is very difficult to see in what way this amounts to exploitation, since it is not known why the abortions were carried out 50 or so years ago.  If the cell lines were not used for medical research, they would be allowed to perish.

“Even if the abortions are thought to be evil, this is an illustration of obtaining good from evil, a commonly encountered phenomenon in medicine. The good of the vaccines and the lives saved or hoped to be saved from their use in the present and future, is being weighed against the alleged evil of historically performed abortions. The cell lines derived from those abortions exist, and the only choice is to use them or not use them. The question then becomes whether not using them is ethically more virtuous than refusing to using them for good purposes.

“Refusal to use vaccines derived in this way will not decrease the number of abortions undertaken today, but it may negatively affect the health of many people in the community. We know that has been the case with many of the vaccines currently in use for measles to hepatitis A. We don’t know whether it will be the case for any COVID-19 vaccine, but if a vaccine works well, it will save lives, improve the health of people, and allow societies to operate in a relatively ‘normal’ way.

“It is interesting that the Pontifical Academy for Life in 2017 expressed the view that, from a Roman Catholic standpoint, use of the most commonly used vaccines in infancy was morally justified, since there was no morally relevant connection between them and the practice of voluntary abortion. Some Roman Catholic commentators today accept that COVID-19 vaccines derived from cell lines from abortions could be used on a temporary basis until more ‘morally acceptable’ vaccines became available.

“The challenge at present is to find an effective and safe vaccine against COVID-19, and the scientific challenges are immense. They are so immense that every strategy available needs to be used against such a catastrophic pandemic. Hence, to quibble about using cell lines stemming from long-gone abortions may sound trite. In an ideal world this may not be the case, and if choices could be made – between cells lines stemming from abortions and others with different origins – many may well opt for the latter. But that does not seem to be the present situation, and the ethically acceptable way is to produce the most effective vaccine or vaccines possible.”

No conflict of interest.

Dr Jeanne Snelling, Lecturer, Faculty of Law and Bioethics Centre, University of Otago, comments:

“According to Science Mag, the two cell lines used in the development of the Covid-19 vaccines were derived from fetal cells obtained from two aborted foetuses, one in 1972 and one in 1985.  At the time that these cell lines were created, it was not unusual for scientists to use tissue or cells obtained in the course of medical procedures for research purposes without consent.  A relatively well-known example of this is the HeLa cell line – a cell line that was created from cancerous tissue removed from a woman called Henrietta Lacks in 1951 (subject of the book by Rebecca Skloot, The Immortal Life of Henrietta Lacks).  The HeLa cell line was pivotal in the development of the polio vaccine, as well as in cancer research, and continues to be used around the world.

Current use of the two fetal cell lines in vaccine development

“The two fetal cell lines used in the current research have certain properties that make them valuable in research.  The original cells from which these historical cell lines were derived would have been obtained in the context of that time—ie without the consent of the woman who underwent the termination.  For some people, the original source of the stem cell line may make them feel unsure about receiving the vaccine—e.g. if they are:

  1. anti-abortion and do not want to use a therapy derived from/associated with a procedure that they are morally opposed to;
  2. are pro-choice, but nevertheless think that obtaining the cells was unethical because consent was likely not obtained from the women involved. In terms of this objection it should be noted that many historical cell lines are ethically ‘tarnished’ in this way.

“To clarify, these historic cell lines were first created decades ago.  The cell lines being used in current vaccine research were derived from those original fetal cells, but are not the same, meaning that the cell lines used now are essentially replicas of the original cells. Finally, although cell lines are used in the production of vaccines, the vaccines themselves do not have actual human cells in them.

“Ultimately, the source of the cell lines used as part of vaccine research and development may be disquieting for some. However this needs to be considered against competing considerations, such as that the circumstances in which the original cells were obtained reflect the prevailing attitudes to research on human tissue at that time; that these cell lines have a proven record in vaccine development; and that the sooner a vaccine is developed and tested, the sooner we will be able to reduce the mortality and morbidity associated with Covid-19.  In this regard it is significant that the Vatican (in an earlier discussion on childhood vaccinations) has observed that in the absence of alternatives, Catholics could, with a clear conscience, receive clinically recommended vaccines made using historic fetal cell lines*.

Collection and use of fetal tissue or cells: regulatory framework in NZ

“Collection and use of fetal cells or tissue obtained from a dead foetus is governed by the Human Tissue Act 2008. The purpose of the Act is to ensure that collection or use of human tissue only occurs with proper recognition of, and respect for, a range of ethical values. The Act requires informed consent to collection and use of such tissue (in this case informed consent would generally be given by the woman/mother) and any research should be approved by an ethics committee.

New Zealand’s policy regarding embryo research and embryonic stem cell research

“New Zealand’s current regulatory approach makes a distinction between the use of existing embryonic stem cell lines for research, and conducting original embryonic stem cell research. Currently, researchers may import existing embryonic stem cell lines for research purposes. This ‘compromise’ position enables limited stem cell research to be conducted, but does not permit original embryonic stem cell research. For some, this compromise position is problematic: if it is ethically permissible to use imported stem cell lines, it seems inconsistent to prohibit original stem cell research. In general, the scope of embryo research is very limited in NZ, which only permits the use of non-viable embryos in research (pursuant to Guidelines formulated under the Human Assisted Reproductive Technology Act 2004).”

*Vatican’s Pontifical Academy for Life (2005) released a document “Moral Reflections about Vaccines Prepared from Cells of Aborted Human Fetuses’ and published further clarification in its Note on Italian Vaccine Issue (Rome, 31 July). Against the background of decreasing vaccination for childhood conditions like measles and rubella, it clarified that because: the cell lines are historical, and because “the ‘wrong’ in the moral sense lies in the actions, not in the vaccines or the material itself”; and because of the moral obligation to guarantee vaccine coverage especially for vulnerable subjects, then “clinically recommended vaccinations can be used with a clear conscience and that the use of such vaccines does not signify some sort of cooperation with voluntary abortion”.  Therefore (and only) in the absence of alternatives, Catholics could in good conscience receive vaccines made using historical human fetal cell lines – but should share a commitment to developing vaccines without a connection to abortion.

No conflict of interest declared.