The National Catholic Bioethics Center considers what I think is a straw-man argument against people who reject mRNA vaccines on ethical grounds because they're transhumanist.

Myth 1: For vaccines that rely on injecting patients with mRNA, the possi­ble incorporation of these genes into our genetic makeup will fundamentally alter who we are as humans, moving us into a project of Transhumanism, the production of a “Human 2.0,” etc.

Reply: Any incorporation of new genes into our chromosomes from a COVID-19 mRNA vaccine would be an exceedingly rare occur­rence, if it were to occur at all. It is actually very difficult to get the ge­netic information of mRNA to in­tegrate into our chromosomes, partly because this would mean a reverse directional flow of the so-called Central Dogma of Molecular Biol­ogy: our DNA or chromosomes are read (“transcribed”) to produce mRNA, which is then read (“trans­lated”) to make proteins. Even if the accidental and unintentional incorporation of an mRNA mes­sage into our chromosomes were somehow to occur following vaccination, this would not mean that we were creating “Human 2.0,” since those genetic changes would not be expected to affect our sex cells, and therefore would not be transmitted to the next generation. Vaccinating people with an mRNA vaccine for COVID-19, therefore, does not imply that we are “remaking man” or heading down the path of Transhumanism.


My problem with this statement is that they consider only what is actually happening this year, not the ethics of the abstract idea of mRNA treatments. (i.e., this is what I'd like to ask the Catholic Bioethics center, and I may, but I'll ask here first as a shortcut)

So I have two ethical quandaries that I'd like a Catholic Ethics (i.e. Natural Law) answer from.

  1. If mRNA vaccines look like they're useful, an obvious better vector than a shot for stopping a disease would be to make mankind resistant chromosomally, does the mRNA vaccine represent a staging area for the efficacy of such a treatment and therefore represent a first step in a slippery slope that we should reject?

  2. If mRNA vaccines are not transhumanist in nature, when it is injecting your body with a synthetic mechanism to prevent (not treat) a disease, how is it less transhumanist than replacing your cornea to avoid glaucoma or replacing your prostate to avoid cancer?

  3. Why is it important to inform the public that it doesn't affect the genome? Does something have to affect the genome to be "transhuman"? Bionic eyes and nano-bots would not affect the genome either, but they would be transhumanist. How is turning ones body into a protein generating factory by synthetic means, not transhumanist?

  • I dont know how to word this exactly, but you might consider that they are not outlining any standards or boundaries or even just thinking clearly. They bring up two reasons. It wouldn’t affect future generations, and probably not even our genome. Wait, does lack of transmission to future generations mean it’s ok, or not? If not then why is that the argument? Or is it the argument? Maybe the statement has two purposes, one being to reduce fear and exaggeration of this particular case. But if that spamming logic is their actual basis for advising...
    – Al Brown
    Aug 2, 2021 at 12:19
  • It’s actually a slippery slope to even bring up the idea that maybe lack of generational impact makes it ok.
    – Al Brown
    Aug 2, 2021 at 12:26
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    @AlBrown that's what annoys me about it too. Getting a bionic eye would be transhumanist, but not be passed on to subsequent generations, so why is the near impossibility of passing a gene to your children (assuming the vaccine doesn't make you infertile) make it not transhumanist. It's biohacking pure and simple, and not in a natural way, like an attenuated virus, but in a synthetic way, (a hairsbreadth away from nano-bots) turning you into a protein generating machine.
    – Peter Turner
    Aug 2, 2021 at 13:36
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    Theres some esp good wording to save (your last comment) as maybe a template or starting point, particularly the last sentence
    – Al Brown
    Aug 2, 2021 at 14:21
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    I found a very pertinent 2014 paper Transhumanism and Catholic Natural Law which starts with describing nat. law ethics as is-ought / nature-ethics-telos, then distinguishes first-nature (metaphysical & biological) vs. second-nature (culturally relative), then argues how recent advances in biology moves some portions of the biological nature to the second-nature category, and finally evaluates how the very conception of natural law ethics will need to change depending on our openness to transhumanism. Aug 2, 2021 at 19:46

2 Answers 2


Short answer

  1. By its very mechanism, mRNA technology cannot alter our DNA, but an entirely different technology can, such as CRISPR which is a candidate to make mankind resistant chromosomally. Furthermore, the role of an mRNA vaccine is ONLY to trigger natural immune system response to create necessary antibodies and memory T cells. The vaccine itself does NOT remain, destroyed within a few hours. The vaccinated cells are also killed by our immune system. What remains is only our enhanced immune system that remembers Covid (the actual memory length is still being improved), just like the effect of a regular vaccine. For these reasons, mRNA technology (unlike CRISPR) is not on a slippery slope to Transhumanism.

  2. Since the residue of mRNA Vaccine treatment is simply a better trained but still naturally functioning immune system, taking the vaccine is NOT a transhumanist action (because no new capability is added). Replacing your cornea to avoid glaucoma or replacing your prostate to avoid cancer is also NOT a transhumanist action since the function of the new organ remains the same. Please read the longer answer for the full explanation.

Long Answer

The answer has 4 parts:

  1. clarifying how mRNA is never designed to alter DNA
  2. brief description of the application of natural law reasoning to improve health using medical technology
  3. answering your 2nd question by first establishing the red line separating the allowed vs. disallowed (such as transhumanism) and then explaining the morality of using mRNA for an individual
  4. answering your 1st question by first explaining the morality of the technology development of mRNA and then addressing the concern of slippery slope toward transhumanism by previewing the future use of the mRNA technology

How the mRNA vaccine works

Very short summary

The mRNA vaccine works by giving synthetically constructed instruction to our cells (based on real virus genetic sequencing) to make copies for a part of the virus.

After our cells make copies of the protein, they destroy the genetic material from the vaccine. Our bodies recognize that the protein should not be there and build T-lymphocytes and B-lymphocytes that will remember how to fight the virus that causes COVID-19 if we are infected in the future.

(Source: Understanding How COVID-19 Vaccines Work)

Further study:

mRNA vaccine does NOT modify DNA

By design, an mRNA vaccine is supposed to work only within the cytoplasm of the cell, never entering the area where the DNA resides (the nucleus).

There can be unintentional (but extremely rare) exceptions, but is still not dangerous:

... One is where genetic elements, known as retro-transposons, hijack cellular mRNA, convert it into DNA and insert that DNA back into your genetic material.

This has occurred sporadically throughout evolution, producing some ancient copies of mRNAs scattered throughout our genome, to form so-called pseudogenes.


However, there is a vanishingly small chance of a naturally occurring retro-transposon becoming active in a cell that has just received a mRNA vaccine. ...

Even if a retro-transposon were to become active or a virus such as HIV were present, the chances of it finding the COVID vaccine mRNA, among the tens of thousands of natural mRNAs, is extremely unlikely. That’s because vaccine mRNA is degraded within several hours of entering the body.

Even if vaccine mRNA did become a pseudogene, it would not produce the SARS-CoV-2 virus, but just one of the viral products, the harmless spike protein.

Source: June 2021 article Can the Pfizer or Moderna mRNA vaccines affect my genetic code?

Further Study:

Natural Law application to medical technology

Natural law morality reasoning is built on

  1. what is natural (original design)
  2. final end (proper operation of perfect nature)
  3. intention (goal of action, which needs to be aligned to target the 'final end').

What is the "natural" in this case? The "natural" is the perfect natural human. I emphasize perfect to distinguish it from disability (such as born with one eye, or with Down syndrome) or disease (from common flu to covid to cancer).

A perfect natural human has the best physique & mind possible that Adam and Eve would have had prior to the Fall (except for death), who has the potential to

  • have musical intelligence like Mozart
  • win several Olympic gold medals (without performance enhancing drugs)
  • discover scientific theories like Einstein
  • make inventions like Thomas Edison
  • never be sick, but will STILL die a natural death (through natural degeneration)

I will approach both questions in terms of whether the technology will reasonably align with a natural final end (prevent sickness) with as little non-natural side effect as possible.

Answering your second question


  1. If mRNA vaccines are not transhumanist in nature, when it is injecting your body with a synthetic mechanism to prevent (not treat) a disease, how is it less transhumanist than replacing your cornea to avoid glaucoma or replacing your prostate to avoid cancer?

I answer in two parts:

  • Definition of transhumanism and what types of actions are allowed under natural law
  • Whether the taking of an mRNA vaccine is allowed under natural law

Definition of transhumanism and what is allowed under natural law

Let's use a working definition of Transhumanism as "using technology to permanently add abilities that a perfect natural human will never have".

First let's consider scenarios that are allowed by natural law to highlight certain distinctions:

  1. As long as medical technologies (including mRNA vaccines) are used to prevent sickness and to prolong the life of a person naturally born, I think the actions are still allowed under natural law because these technologies are helping humans to be closer to a perfect but natural human (who should not be sick and who should live to a natural old age). No technologies we know of today can prevent death (when there is, we'll revisit this point).

  2. When the cure of a disability / disease results in enhancing a human's ability beyond what a perfect human could ever be (i.e. titanium leg is stronger, cochlear implant can be more sensitive, artificial heart gives more stamina, tooth implant lasts longer), this is still allowed under natural law because

    • the enhancement is accidental (i.e. the titanium leg, cochlear implant, artificial heart or tooth implant was not given by intentionally ripping out a healthy leg/ear/heart/tooth).
    • the design (intention) is to not to add, but merely to replace, the function of the original organ.
  3. Even proactive replacements of organs are allowed if the case can be reasonably made that the original organ will fail prematurely without intervention, such as in the examples you mentioned: replacing your cornea to avoid glaucoma or replacing your prostate to avoid cancer. The key criteria is the same as in the previous scenario: not to intentionally ripping out healthy organ, not to intentionally add function.

  4. Non-permanent enhancements attached to the body such as the use of night vision goggles by a soldier (to enhance vision) or a bio-neural interface of a fighter jet pilot (to enhance brain) or even semi permanent implants (which can be surgically removed) such as biometric chip (to facilitate security), are also okay under natural law because they are considered tools (by definition, non-permanent) that humans for millennia have used starting from stone age axe and hunting bow.

In contrast, a transhumanist wants to intentionally add a new permanent ability to a healthy individual beyond the potential of a natural perfect human described above. Hypothetical examples: genetic enhancement that produce humans like X-men, implanting a computer in the brain to enhance cognitive function, adding a third arm genetically / biologically. Permanent intentional non-accidental addition is the red line separating allowed vs. disallowed action under natural law.

Whether the taking of an mRNA vaccine is allowed under natural law

The concern is because the mRNA vaccine is synthetic, proactively done (as in scenario #3) and potentially enhances our immune system beyond the usual (as in scenario #2, see Immune Response From mRNA COVID-19 Vaccines Is More Robust Than Natural Infection).

As is usual in natural law, the scope of morality is the single action evaluated on a case by case basis. The scope here is whether the individual's decision to take the shot of an mRNA vaccine is allowed. I think it is allowed because the intention is to prevent sickness and the course of action aligns with a final end that is natural (i.e. consistent with the natural functioning of the immune system; the enhancement itself is accidental).

Whether the vaccine is synthetic (mRNA) or natural is irrelevant in this case, since the end result in BOTH cases is the SAME: that our natural immune system is being "trained" to fight future real-virus infection. It is similar to the training data for a neural net model in a machine learning system. The only difference is that the mRNA vaccine (which is synthetically generated, and which disappears within a few hours) uses our body to create the actual training data. Neither the mRNA vaccine nor the partial-virus copies (the training data) modifies the DNA or cross the germline since both operate only within the cytoplasm area.

CONCLUSION: the taking mRNA vaccine lies within scenario #3 (proactive prevention of the failure of a natural function), similar to proactive cornea/prostrate replacement when there is a reasonable chance that the immune system / cornea / prostrate would be endangered in the future if we do not take action. This is similar to vaccinating kids with polio / smallpox vaccine. All of these are NOT considered transhumanist actions.

Answering your first question

Now we are ready to address your first question, which deals with the technology development rather than the moral situation of taking the vaccine:

  1. If mRNA vaccines look like they're useful, an obvious better vector than a shot for stopping a disease would be to make mankind resistant chromosomally, does the mRNA vaccine represent a staging area for the efficacy of such a treatment and therefore represent a first step in a slippery slope that we should reject?

As described in the first section above, we need to keep in mind that the mRNA technology so far:

  1. is not designed for the intentional modification of the DNA (only staying in the cytoplasm, not in the nucleus)
  2. is only used to bolster the natural human immune system for a natural end (prevent sickness)

Intention-wise (as far as natural law is concerned) it is thus the same with the older vaccine technologies that we have been using such as polio & flu (inactivated), smallpox (virus vector), measles (live-attenuated), hepatitis B (protein subunit) (see the article linked above).

How about the future use of mRNA? A Jan 2021 interview with Derrick Rossi (co-founder of Moderna) discussing future use of the mRNA technology within 15 years shows the following application:

  • creating vaccines for other diseases such as flu
  • treatment for diseases such as cystic fibrosis, cancer and HIV
  • make advances in anti-aging research

A more extensive March 2021 article from Wired magazine previews more potential use of mRNA technology: The mRNA vaccine revolution is just beginning.

From those articles we can see how the projected path of mRNA development in the next 15 years is still limited to fighting diseases and prolonging life.

While there are signs that mRNA could add unnatural functionality (mice injected with mRNA encoded for the protein that makes fireflies light up causes the mice to have a glowing spot one hour later), the addition is temporary, and is usually only for diagnostic / experiment (see this paper In a possible step forward for gene therapy, Stanford researchers made mice glow like fireflies). As long as the mRNA use is intended for gene therapy it is still allowed by natural law.

A more relevant technology that a transhumanist would use is CRISPR, a tool to edit DNA for permanent effect. If one uses CRISPR to edit unborn fetus's DNA, it is possibly against natural law, but still depends on the intention of use. It is probably okay if it is to prevent future sickness (which makes it to fall under scenario #3).

CONCLUSION: Given the projection of the use of the mRNA technology in the next 15 years and given the inherent limit of its applicability (temporary effect), mRNA technology is NOT likely to be on a slippery slope to transhumanism, compared to CRISPR which certainly IS.

  • Sound logic, but I think the first answer contradicts the second answer. mRNA vaccines intentionally seek to supplant the normal reaction caused by attenuated vaccines or naturally caught viruses. The fact that we're using synthetic means to prevent an illness means we've taken a tiny step towards a transhumanist future. To follow your bullet points, it is intentional (so far at least), permanent (maybe) and proactive in a way that inhibits the natural immune response, especially in people who have already been exposed to the virus.
    – Peter Turner
    Jul 27, 2021 at 18:25
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    @OneGodtheFather From the various articles I linked in my answer (esp. Paul Offit and Wired magazine article), the answer seems to be definite NO (even covering the next 15 years), while other technologies DO (like CRISPR) simply by how mRNA works. This confirms what the quote in the OP says about how difficult it is for RNA to crossover to DNA. Accidents can happen, but future applications never seem to intentionally use DNA. Jul 27, 2021 at 22:30
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    Re "...create necessary antibodies": That is not all. More important, at least for the long run, are T cells, e.g., memory T cells. Jul 28, 2021 at 0:18
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    @PeterTurner mRNA vaccines are not "a synthetic replacement for a naturally functioning immune system". mRNA vaccines and attenuated viruses are pretty similar in what they do. The attenuated virus also introduces the blueprint for viral parts that the immune system can detect. The difference, as far as I understand, is that the mRNA vaccine is synthetic and ONLY encodes specific proteins, while an attenuated virus has building instructions for more than just that specific protein (it's the whole virus, basically). A virus is just (more) RNA (or DNA, depending on the virus) in a shell.
    – kutschkem
    Jul 28, 2021 at 8:47
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    @curiousdannii I agree. I think I can find something for the 3 Natural Law principles but I haven't found specific application of those principles to medical interventions that "enhances" / "cure" human body, maybe because it's not controversial in the first place! Rather, most of them only deal with abortion, reproduction, euthanasia, etc. Even the "Transhumanism and Catholic Natural Law" paper seems to be NOT suitable for this answer, since it seems to argue (or a thought experiment) for modifying natural law to adapt to the changing human nature, i.e. for embracing transhumanism! Aug 3, 2021 at 5:31

1 isn't really a question that we can answer. It's speculative. Are current mRNA vaccines a staging ground or first step on a slippery slope? You'd need to show that mRNA vaccines necessarily or at least very plausibly lead to transhumanism. As far as I am aware, mRNA vaccines can't change your genetic code, and that accords with the basic biology I learned in high school and college. I'm by no means an expert. Someone asked for a link on this, the CDC states that mRNA vaccines don't alter your genes: https://www.cdc.gov/coronavirus/2019-ncov/vaccines/different-vaccines/mrna.html

2: Unless mRNA vaccines actually do change your genetic makeup, which needs to be supported by evidence, they are by definition not transhumanist. It's not human enhancement, it is just like every other vaccine. You're injecting yourself with something that stimulates an immune response so that your body has antibodies with which to fight the disease. From what I understand (again, I'm not an expert), the advantage of mRNA vaccines is not in their efficacy, but in their ease of development. They can be developed much more quickly than traditional vaccines. This is necessarily different from outright replace body parts with "better" synthetic versions

I think that the bioethics center response to "myth 1" answers your questions. mRNA does not change DNA. DNA is the template. mRNA builds proteins. They are rejecting the notion that this is "heading down the path of Transhumanism" because no one as yet has presented a reason to think that is plausible. If you could show that mRNA vaccines really will lead to transhumanist practices, or that they really are transhumanist in themselves, I'm sure Catholic ethicists would then agree that they ought to be rejected on moral grounds.

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    +1 There goes my chance to be a Terminator!
    – Ken Graham
    Jul 27, 2021 at 14:26
  • Instead of being transhumaned, be transfigured.
    – jaredad7
    Jul 27, 2021 at 14:27
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    My initial thought is Elon Musk is not understanding mRNA. A lot of futurists in general aren't really experts in much of the technology they tout. I believe Elon wants mRNA to lead to Bioshock type super powers, but the fact is that there just isn't any support that mRNA vaccines will plausibly lead to this. That's why you're getting the answer you're seeing on the NCBC website.
    – jaredad7
    Jul 27, 2021 at 14:47
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    @OneGodtheFather I have this in my answer (see the section about how the vaccine doesn't modify DNA). Jul 27, 2021 at 22:09
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    @OneGodtheFather here you go: cdc.gov/coronavirus/2019-ncov/vaccines/different-vaccines/…
    – jaredad7
    Jul 28, 2021 at 13:37

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