1To me, perhaps the most annoying false claim out of the many that have been made about the COVID vaccines is that they are some sort of "gene therapy." Unscrupulous activists have preyed upon the anxieties of people in ordinary times, and the fear which has been generated during the COVID-19 pandemic has taken this to an extraordinary level.
We live in an age of technologies that are generally only dimly understood by most people, yet we depend upon them daily. The level of technical education needed to make informed decisions about them is something our democratic and legal processes struggle with. Unlike politicians, legislators, or judges, most people don't have scientific advisers or expert witnesses to help them figure out who's telling the truth, or who to believe. The credibility of our institutions that has been lost in recent decades due to the politicization of science has only made things worse. It's a difficult problem for governments that get their legitimacy from the consent of the governed, when the people who are voting on who will best represent their views on policy issues lack the information they need to make a reasoned choice, or can't trust what information they do get.
So what exactly is "gene therapy," and why can't the COVID vaccines do that? To understand why requires some review of the basics in biology, and understanding the basics of our technological world is perhaps the best way to solve the policy problem I just mentioned. I'll try to outline it briefly, and you can just skip ahead if you already know this stuff.
For humans, the programming that enables us to turn from a single cell in our mother's womb to build a baby with all his or her various organs and tissues that can survive in the outside world is found at the center of our every cell, in the long stringy molecules called DNA. Though DNA is packaged into chromosomes, which look kind of like microscopic packages of yarn, to keep them organized and compact within the nucleus of our cells; they function more like molecular recording tape, for those old enough to remember what that was.
(Photo credit: Futurity.org)
For purposes of my explanation, you need to know that DNA has two copies of its data, or strands, which match up with each other and twist around each other like the strands in a rope. When cells are about to divide, the two copies are unwound from each other, and a new matching copy of the data is assembled onto each strand, making two new double-stranded DNA molecules, each of which will go into one of two new cells when they split apart. This is a process that happens trillions of times during our development from that first single cell, through to our growing into an adult, and when we heal.
Viruses, however, are very much simpler --so simple in fact that its almost as though they're not "life" in any form we're familiar with. Though there are some viruses which contain DNA, the coronavirus that causes COVID, known as SARS-CoV-2, uses a different stringy molecule for its programming, RNA. RNA is single-stranded, unlike DNA, which is double-stranded. Viruses cannot reproduce themselves unless they can infect a cell which has the necessary molecular "machinery" to build new viruses from the viral “program” they carry. RNA-based viruses take advantage of the fact that cells of higher organisms, such as humans, use RNA copies of their DNA (called "messenger RNA," or mRNA) to instruct their molecular "machinery" how to make all the proteins needed to build, for example, a new baby, or to heal.
The scientists who invented the mRNA-based COVID vaccines used one of the parts of the SARS-CoV-2 virus RNA, which contains the program (or gene) for how to make the part of SARS-Cov-2 called the "spike protein," to make just that one protein, which is what the virus uses to stick to target cells it's going to infect. That way, when this foreign protein shows up, our immune systems are already prepared to attack it, since they've already been trained against the "spike." Trouble is, out in the environment, "variants" of the SARS-CoV-2 virus which make a different form of "spike" have already evolved, which evade the protection of the vaccine against the first virus. Due to the fact that viruses reproduce incredibly fast, and are very simple, with relatively few genes, they can evolve far more rapidly than most other forms of life (if you can even call a virus "alive").
One of the basic processes in the cells of most life on Earth, aside from viruses, is how the genes in DNA get copied to messenger RNA, and then proteins are made based upon those genetic instructions. This process is called "translation," because the information in DNA gets translated from DNA, to RNA, to protein, as though these different molecules are different languages.2 This translation of information, with one exception, only happens one way. You cannot go back from protein, to mRNA, to DNA. The exception is that some RNA viruses (but not SARS-Cov-2!) have a protein called reverse transcriptase, which uses RNA to make DNA. These viruses, called "retroviruses," can actually hide out in the DNA of the cells they infect, by copying themselves into the DNA of their hosts. The human immunodeficiency virus (HIV), which causes "Acquired ImmunoDeficiency Syndrome" (AIDS), is one form of retrovirus. Another retrovirus, called HTLV (human T-lymphotrophic virus), causes a form of leukemia in humans.
The process by which the RNA-based retroviruses copy themselves into the host cell requires another viral protein besides the reverse transcriptase, called an "integrase," which enables the DNA copy of the RNA virus to be inserted into host DNA. Scientists looking to cure genetic diseases in humans have had some limited success in using the processes used by retroviruses to repair defective genes in human cells, by integrating the normal version of the gene into human cells and then putting those repaired cells back into the patient, but this is still experimental. Such "gene therapy" is not something that could occur from an mRNA vaccine without reverse transcriptase and integrase, which are not found in the SARS-CoV-2 virus, or the mRNA vaccine derived from it. Without those retroviral proteins, changing human DNA by introducing foreign RNA is just not going to happen.
However, over the course of human evolution, the DNA of our species has been attacked many times by retroviruses, whose remnants are still present in our DNA today. These ancient retroviruses, called "Human Endogenous RetroViruses," or "HERVs," are maybe as much as 8% of our DNA, and scientists are now studying them to determine if they may play a role in human diseases which we don't currently understand the causes of, including the possibility that they may be another process that could initiate cancer.
Overall, there are but a few known processes that lead to the development of cancer: either the genes that in ordinary development and healing promote cell division become defective, producing uncontrolled growth, or the genes that tell the cells to stop dividing become defective, also producing uncontrolled growth. At the DNA level, we have genes which program for our cells to divide and grow, called "oncogenes," and other genes, called "tumor suppressor" genes, which turn the process of cell divison off when they're supposed to. Another process that can contribute to cancer is if the cells of the immune system which are responsible for identifying and destroying defective cells aren't working right for some reason, and the defective cells which occur from time to time in our bodies are not destroyed as they're supposed to be. Exposure to certain chemicals that can harm DNA, or exposure to high-energy radiation, can cause damage to oncogenes or tumor supressor genes, and start the process of cancer. And as we know now, some viruses can also cause cancers, notably human papilloma virus, or HPV, which causes most cervical cancer. HPV is a DNA-based virus, which doesn't need a reverse transcriptase to integrate into the host cell DNA, and is sexually transmitted. There is also a vaccine for it.
Viruses which can integrate into DNA, like RNA-based retroviruses do, apparently cause cancer by inserting themselves into the host DNA in a way which interferes with the oncogenes or tumor supressor genes, and given that there are retroviruses already present in the human genome from our evolutionary history, the HERVs, the concern is that they might still be functional to some degree, though most appear to have been degraded by mutations over evolutionary history such that they no longer can produce viral proteins like reverse transcriptase or integrase. But could these hidden ancient viruses that have become a part of us interfere with other necessary genes and cause other human diseases that we don't yet understand the causes of? Or, if some HERVs could still produce reverse transcriptase and integrase, could introducing foreign RNAs from a vaccine cause it to become incorporated into our genome?
That seems extremely unlikely, since if HERVs already present in human cells were producing reverse transcriptase and integrase in enough quantity for that to occur, the retroviruses which infect us from the environment wouldn't need to have genes for making those proteins, they could just use the HERV version of those proteins. Also, RNA-based viruses from the environment which lack the genes that would make them retroviruses, could use those hypothetical HERV reverse transcriptases and integrases as well, and soon we'd have all kinds of integrated viruses in our DNA beyond the ones we already know are there. And that's all without considering mRNA introduced from a vaccine. So, as I said, extremely unlikely. mRNA vaccines are not "gene therapy," and can't change your DNA.
I'll leave you with this interesting perspective from cancer researchers. In development, as we grow from a single cell into a fully-formed baby, there are different ways our cells as they divide know how to get to the organ or tissue they're supposed to be a part of. Sometimes they're following a chemical signal given off by nearby cells that diffuses out in a gradient, and sometimes, as they grow they encounter other cells of a different type, and on contact with them will stop growing, or differentiate into a different type of cell based upon their relative position to their neighbors. Cancer cells, when they form, have some of these same processes, but are different from the other cells in the body. Their genes regulating cell division are broken, so they don't stop dividing when they're next to other cells. But sometimes they do go wandering off throughout the body as though searching for the organ or tissue that they're supposed to belong to.
We call this process "metastasis."
I published this article as a “thread” earlier, when it should have been a “post.”
Technically, only the copying of the information from RNA to protein is called "translation," while copying from DNA to RNA is called "transcription," but I've simplified the terminology for purposes of this explanation.