Once the new COVID-19 mRNA vaccines from Pfizer/BioNTech and Moderna were both announced to have very high safety and effectiveness, the anti-vaccine religion began its disinformation campaign using fear, uncertainty, and doubt. I won’t link to any of those ignoramuses who are posting this garbage, because I don’t want them to have any traffic that comes from this article. But I am sure if you’re following the world of COVID-19 vaccines, you have heard some of it.
I’m going to delve into the world of mRNA vaccines while trying to refrain from giving a cell biology lecture. Unfortunately, it’s going to take a cell biology lecture to explain how mRNA vaccines work, and how there are no biologically plausible reasons to hypothesize that mRNA vaccines can harm your DNA. None. Nada. Nichts.
How do mRNA vaccines work?
I’ve written this several times with regards to both the Pfizer and Modern mRNA vaccines, but it bears repeating.
The Pfizer and Moderna Therapeutics COVID-19 vaccines are mRNA vaccines that rely upon an mRNA, or messenger RNA, molecule to induce an immune response. However, it does not do this directly.
Normally, during the process called transcription, RNA polymerase makes a copy of a gene from its DNA to mRNA as signaled by the cell. In other words, the mRNA sequences in the cell usually correspond directly to the DNA sequences in our genes. These mRNA sequences “carry” that genetic message to a ribosome for translation, where tRNA triplets, which code for one amino acid, attach to the appropriate mRNA triplet, adding one amino acid to the protein chain.
As in DNA, genetic information in mRNA is contained in the sequence of nucleotides, which are arranged into codons consisting of three ribonucleotides each. Each codon codes for a specific amino acid, except the stop codons, which terminate protein synthesis.
AT this point, note that the mRNA does nothing to the DNA strand in your genes – it merely reads the sequence.
Yes, that’s a lot of cell biology, though I took years of courses in cell biology, so trust me when I say I barely touched the surface. If you want to take a deep dive into the science of mRNA and mRNA vaccines, my friend Edward Nirenberg wrote two articles that will satisfy your desires – they really make it clear how this all works and doesn’t work.
However, here’s a basic video that shows how this works.
Alan McHughen, in his outstanding book, “DNA Demystified: Unraveling the Double Helix,” describes how mRNA works:
When an mRNA strand exits the nucleus and enters the cytoplasm, it attaches to ribosomes, and this is where protein synthesis progresses. The ribosome reads the base sequence of the mRNA, three bases at a time. Each three-base triplet, called a codon, specifies a particular amino acid, except for a few with regulatory functions (e.g., UGA =“Stop!”).
If the first three-base codon is AUG, then a molecule of the amino acid methionine is brought into place. If the next triplet is AAA, that brings in the amino acid lysine. The methionine and lysine molecules are attached together. The next triplet is, say, GCC, and that brings in alanine, which is attached to the lysine. The ribosome has read nine bases, AUGAAAGCC, and compiled a short chain of three amino acids, abbreviated Met-Lys-Ala, or MKA (see amino acid abbreviations here).
The ribosome continues reading all of the mRNA bases until it hits a stop signal—which is also a triplet codon such as UGA—and the now long chain of amino acids falls loose. This chain may be a functional protein immediately, or, more usually, it might undergo some additional post-translational processing by enzymes to become active.
Once the mRNA has created a protein, it is then ripped apart by enzymes in the cell, so that the individual RNA nucleotides can go back to being reused in a whole new mRNA sequence. The cellular machinery of translating DNA into proteins is constantly recirculating itself.
The mRNA vaccine technology relies upon a specific mRNA sequence to kickstart the endogenous production of proteins that are structurally equivalent to the viral antigens. The mRNA sequences in the vaccine enter the cell (with a carrier protein), heads to the ribosomes to create the SARS-CoV-2 antigens. These antigens will depart the cell and will trigger the body’s adaptive immune system to produce antibodies effective against the actual target, in this case, the S-protein or spike on the SARS-CoV-2 virus.
One more thing – the antigens produced by these mRNA sequences are biologically inert. They will induce an immune response, but they will not cause any other biological effect including becoming pathogenic.
So, let’s summarize. The mRNA vaccines make use of the cell’s ribosome to create the S-protein of the SARS-CoV-2 virus. That antigen induces an adaptive immune system response which will “remember” that antigen allowing the immune system to quickly attack the virus if it shows up.
Pfizer COVID-19 vaccine news – should we pump the brakes just a bit?
Moderna COVID-19 vaccine – more good news that requires skepticism
But those mRNA vaccines are going to mess with my DNA!
No. If you paid attention to what I wrote in the previous section, you should have noticed that the mRNA molecule merely reads the DNA information and carries it to the ribosome. It does not change the DNA message in any way, it’s not how the whole process of translation works.
Furthermore, the mRNA from the mRNA vaccines don’t interact with your DNA in any way. They cause the ribosome to produce the S-protein antigen, and that’s it. Once they create precisely one copy of the molecule, the mRNA is broken down into individual nucleotides to be reused by the cell. And in case you were wondering, RNA nucleotides are the same whether they’re manufactured by cells or in a test tube. They are molecularly exactly alike.
If mRNA could functionally change the DNA, it would open up a whole world of genetic medicine. We could fix all kinds of genetic diseases with this mechanism.
But that’s not how mRNA works, so we can’t.
Now, there is one way that mRNA could change genes, and that’s through an enzyme called reverse transcriptase, which generates complementary DNA (cDNA) from a viral RNA template. However, reverse transcriptase does not exist in humans except in the presence of retroviruses like HIV. In that case, it’s using its own viral RNA template, not just pulling random mRNA out of the cell. It wants the cell to produce a bunch of new retroviruses by hijacking the DNA.
Although I haven’t read anything about it, I suppose that there might be some concern that these vaccines should be contraindicated for those with HIV and other retrovirus infections, but S-protein mRNA would not be the biggest concern to individuals with these infections.
There are actually other reasons why these mRNA vaccines are not going to affect your DNA:
- Your cells’ genome (DNA) is contained within the nucleus of the cell, which is surrounded by a double-membrane. It allows for large molecules, such as mRNA which has read the DNA, to leave the nucleus, but blocks large molecules from entering it. So the S-protein mRNA from the vaccine will not enter the nucleus until it is broken down into individual nucleotides, at which point, they are exactly the same as all of the other nucleotides.
- Even if the mRNA molecule could affect the DNA and even if it could get into the nucleus, there are all kinds of error correction machinery in our DNA to keep out random bits of code. With trillions of cells in each human, each containing billions of DNA base pairs, there are naturally a lot of errors that could kill a human if the quality control machinery of the DNA didn’t keep close watch over errors.
- Similarly, this mRNA cannot get into the mitochondria (which have its own DNA) and cause damage to its DNA. Even though the mitochondrion lacks a cell nucleus, it does have its own ribosomes and genes, and they would react to the S-protein mRNA in the same ways as the cell – it would not change its DNA.
Now, there might be reasons to have concerns about the mRNA vaccines. First, we don’t have any long-term data on the effectiveness of the vaccine. Right now, we just have data from a few weeks, so we have no clue if the immune response wanes over time, whether that’s a few months or a few years.
Similarly, we don’t have long-term data on the safety of the vaccine, although I am much less concerned about this. There is some small (I mean tiny) possibility that the S-protein could induce some immune cross-reactivity that leads to an auto-immune disorder, but I’ve seen nothing that would indicate this.
Finally, I remain concerned about the distribution of these vaccines since they need to be shipped under very cold conditions. Anywhere along the distribution chain, there’s a possibility that the vaccine could spoil, and an ineffective vaccine might be given to someone.
But I can tell you one thing – I have no concerns about the mRNA vaccines having any effect on my DNA. None. Nada. Nichts.