Is it ever morally permissible to use a vaccine tested or originated with fetal cells obtained from an abortion? The Pfizer vaccine, now available in Alaska, used such cells for testing.

COVID vaccine pic

Natural Law recognizes three components of any moral action: The object (definition of the act); the purpose for which it is done, and the pertinent circumstances surrounding it.

The object should always be considered first and foremost, since if the object is intrinsically evil, no amount of good intentions or extenuating circumstances can make it morally licit. Aristotle’s example in the Nicomachean Ethics is that even though virtue ordinarily lies in the mean between too much or too little recreation, work, food etc., there is no right amount of adultery because it’s per se wrong. The definition or “object” of vaccination is to use the natural immune capacity of the body to actively oppose foreign agents, by introducing into the body a small amount of an infectious agent, or one which has been rendered harmless, or a synthetic one which mimics a naturally occurring one. Nothing in this definition opposes Natural Law.

However, though no intrinsically evil action may be excused by circumstances or purpose, even intrinsically good or neutral acts may be rendered evil by circumstances or purpose, and evil ones made worse. So, it is necessary to consider these elements also.

As to the purpose of vaccination per se, there is no contradiction of Natural Law, but the circumstance of cell lines derived from aborted fetuses is clearly problematic. No vaccines actually “contain” fetal cells, but this does not eliminate the moral problem of using a vaccine which has utilized fetal cells originating in an abortion for the production or testing of the vaccine. A complete comparison of the 20 available or developing vaccines is available here.

Formal cooperation is voluntary consent to the evil act and is always wrong.

As noted above, it is never morally excusable for evil to be done for any purpose or under any “extenuating circumstances.” No good end can justify an evil means. However, when unavoidable, an evil may be endured; cooperated with, for a sufficiently outweighing good end, and even then only if circumstances sufficiently distance the cooperator from the evil action. We all face such situations often. May one take out an ad in a liberal newspaper if it’s the only one available? What about driving a bus which carries an ad for a pro-abortion political candidate?

To decide such questions, it is crucial to make two distinctions. Cooperation with evil is either formal or material.

Formal cooperation is voluntary consent to the evil act and is always wrong. In material cooperation the cooperator does not will but foresees that his cooperation will be abused to perform an evil. Material cooperation is either immediate or mediate. Immediate cooperation is assistance in the actual performing of an evil act, while mediate cooperation merely makes the performance of the evil act easier and may vary greatly as to closeness or remoteness from the evil. The bottom line morally is that given sufficient removal from the evil act, and for a proportionately grave reason, mediate material cooperation with evil is morally licit.

Fr. Arnaud Selegny, M.D., provides a clear and concise analysis of all these considerations vis-a-vis the COVID-19 vaccines. Fr. Araud emphatically acknowledges that “one should, as far as possible, avoid cooperation in evil, even material,” and that we must do everything possible “to influence the pharmaceutical industry to develop their new vaccines on cellular carriers that do not pose any moral difficulty.” Furthermore, “If there exists a vaccine derived from cells not obtained from an abortion, and it is available, it is the one that must be used.” Still, “The doctor who vaccinates a patient, or the patient who is vaccinated, has only distant cooperation, for these acts only encourage and promote the sin of abortion in a very remote and very slight way. For sufficient health reasons, such acts could therefore be morally permitted.” (The abortions were done 35+ years ago.)

It is essential to note that what is permitted is never the doing of an evil, but only unavoidable toleration of remote material cooperation with evil for the purpose of a proportionate good. Also, this analysis does not intend any implication as to the effectiveness, safety, or ultimate goals of the implementation plan of the Pfizer vaccine in Alaska. Such circumstances have a role in deciding the morality and desirability of accepting the vaccine, but they are beyond the intended scope of this consideration.

The writer holds a Masters Degree in religious studies and a Pontifical Catechetical Certificate from Notre Dame Institute. She lives in Anchorage.

The views expressed here do not necessarily represent those of the Alaska Watchman.

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ANALYSIS: Is the Pfizer COVID vaccine morally licit?

Therese Syren
Therese Syren is a long-time pro-life advocate in Alaska who helped found a local sidewalk counseling outreach outside an Anchorage abortion clinic. She holds a Master's Degree in Catholic Theology and a Pontifical Catechetical Diploma.


  • Joyful says:

    With great respect, I wanted to point out that the statement, “No vaccines actually “contain” fetal cells, ” found in the third paragraph is incorrect. Here is a video by Theresa Deisher, Phd, concerning aborted fetal cells and if they are actually in our immunizations:
    Note that it says that the “video ended last year” but the link still works.  I last checked it today on 1/8/21.

  • Joyful says:

    Correction: “No vaccines actually “contain” fetal cells,” is found in the fifth paragraph. Sorry for the mix-up!

    • John says:

      We can all read, but your point isn’t the intended take away. I think the point is that abortion cell were used in research, testing and development of the Pfizer vaccine.

  • Burt says:

    Evil is evil, Sin is Sin, and it matters not if it was done 35 years ago or 35 days ago.

  • AKFireFlower says:

    Thank you for this article.

  • Dalton Fox says:

    Very informative, I have been looking for the vaccine contents and info. I how have it posted on my desktop from your link.
    Thank you!


    Thank you for the article. I wonder if Jesus ever committed any acts for “sufficient reason” despite a background of evil, no matter how remote? Something to pray about.