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FAQ on the Use of Vaccines


What is the Church's teaching about the use of certain vaccines that have a distant historical association with abortion?
There are a number of vaccines that are made in descendent cells of aborted fetuses. Abortion is a grave crime against innocent human life. We should always ask our physician whether the product he proposes for our use has an historical association with abortion. We should use an alternative vaccine if one is available. 

What does it mean when we say that these products are made in "descendent cells"?
Descendent cells are the medium in which these vaccines are prepared. Two of the earliest and best-known cell lines, WI-38 and MRC-5, were begun using cells taken from one or more fetuses aborted years ago. Since that time the cell lines have grown independently. It is important to note that descendent cells are not the cells of the aborted child. They never, themselves, formed a part of the victim's body.

How does one know when a particular vaccine has an association with abortion?
Cell lines such as WI-38, MRC-5, HEK-293, PER C6, WI-26 VA4, and Walvax-2 are derived from tissue from aborted fetuses. Any product grown in these or other cell lines derived from abortions, therefore, has a distant association with abortion. The cells in these lines have gone through multiple divisions before they are used in vaccine manufacture. After manufacture, the vaccines are removed from the cell lines and purified. One cannot accurately say that the vaccines contain any of the cells from the original abortion.

What does one do if a physician recommends one of these vaccines?
Sometimes alternative products, which are not associated with these cell lines, are available for immunization against certain diseases. For example, there are a rabies vaccine (RabAvert) and a single dose mumps vaccine (Mumpsvax) that have no association with abortion and that are equally safe and effective. If doing so is practical, you should ask your physician to use an alternative vaccine, but there is no moral obligation to use products that are less effective or inaccessible. Parents should check with their physician regarding the efficacy and availability of these and any other vaccine.

Are there any vaccines for which there are no alternatives?
Unfortunately, at present there are no alternative vaccines available in the United States against rubella (German measles), varicella (chickenpox), and hepatitis A. All of these are grown in the cell lines WI-38 and/or MRC-5. 

What do I do if there is no alternative to a vaccine produced from these cell lines?
One is morally free to use the vaccine, despite its historical association with abortion, if there is a proportionately serious reason for doing so. In practice, the risks to personal and public health could permit its use. This is especially important for parents, who have a moral obligation to protect the life and health of their children and those around them.

What support is there in Church teaching for this position?
A statement from the Pontifical Academy for Life issued in 2005 holds that one may use these products, despite their distant association with abortion, at least until such time as new vaccines become available. The Vatican instruction Dignitas personae (n. 35) states that “grave reasons may be morally proportionate to justify” the use of  these products, “for example, danger to the health of children could permit parents to use a vaccine which was developed using cell lines of illicit origin, while keeping in mind that everyone has the duty to make known their disagreement and to ask that their healthcare system make other types of vaccines available.” It concludes with a reminder that we are living “in the context of the urgent need to mobilize consciences in favor of life,” which points to the importance of avoiding scandal and giving witness to the dignity of every human life.

What can I do to ensure that alternative vaccines will be made available?
You can write to the pharmaceutical companies that make these products and insist that they manufacture vaccines that can be used by all without moral reservation. You can contact your local legislators about your concerns. You can also urge health care systems and providers to encourage pharmaceutical companies to develop ethically sourced alternatives, urge Catholic dioceses and bishops to speak with Catholic systems in their jurisdictions about this, or band together with other individuals to form larger groups requesting change, which would be more likely to have an impact.

Am I free to refuse to vaccinate myself or my children on the grounds of conscience?
One must follow a certain conscience even if it errs, but there is a responsibility to inform one's conscience properly. The vaccination question is a multifaceted one, where the difficulty of accessing accurate, unbiased, reliable, and credible information may lead people to different conclusions in good faith. In any case, there must be serious reasons for refusing immunization against dangerous contagious diseases, for example, rubella, especially in light of a proper Christian concern for personal health, the health of children and others who are vulnerable, public health, and the common good.

Won't my use of these vaccines encourage others to destroy human life for research purposes? 

There is only a distant connection between immunizations today and the abortions from which cell lines such as WI-38 and MRC-5 were derived, but Walvax-2 is an abortion-derived human fetal cell line introduced in 2015. Furthermore, there are ongoing efforts to justify unethical research (such as research to create human embryonic stem cells) and federal funding for research on fetal tissue (which is obtained from providers of elective abortion like Planned Parenthood) by pointing to the benefits of vaccines derived from elective abortions. While these facts alone do not make the use of existing vaccines immoral, as explained above, failure to adequately protest and/or to demand alternatives to these vaccines can contribute to moral complacency on this critical issue. This can encourage people to continue to justify, and to benefit from, the destruction of human life via elective abortion.

© The National Catholic Bioethics Center, 2006; rev. 2019.