Do mRNA vaccines affect my DNA?

In this week's Pandemic Problems column, a reader asks how to explain mRNA vaccines to a worried family member

By Nicole Karlis

Senior Writer

Published May 5, 2021 6:30AM (EDT)

Man refusing to get injection of vaccine (Getty Images)
Man refusing to get injection of vaccine (Getty Images)

Dear Pandemic Problems,

I have a family member who has concerns about mRNA, and if the mRNA in the vaccine can adversely affect his DNA. I don't understand mRNA. Where can I get reliable information on this question?


Confused by mRNA

Dear Confused by mRNA,

I typically only focus on answering questions about social qualms that have come up during the pandemic — like a husband-wife rift because of one partner refuses to get vaccinated. But after reading your question, it became even more clear to me that journalists like myself, and public health experts, could do better when it comes to explaining mRNA vaccines and why they're safe.

So many people want this pandemic to be over and won't think twice about getting vaccinated. But there are just as many people out there who are hesitant to get inoculated. As you've probably already read, mass vaccination sites are starting to close across the country because the demand for the vaccine just isn't there. This is problematic because only 30 percent of the adult population is fully vaccinated as of May 4, 2021. (At least 44 percent of the U.S. population has received the first shot of one of the two-dose vaccines.) These numbers, and the fact that vaccination rates are slowing down while less than half of the U.S. population is vaccinated, have led public health experts to wonder whether the U.S. will ever reach herd immunity.

But back to the vaccines themselves. Two of the available vaccines, the Pfizer and Moderna ones, use the mRNA vaccine technology. Both the Johnson & Johnson and AstraZeneca vaccines are viral vector vaccines, which are different.

This is all to say that if one were hesitant to get one of the COVID-19 mRNA vaccines, know this: they're very safe, and they don't cause mutations or affect one's DNA.

So, how do they work?

First, let's start with the basics: mRNA is short for messenger RNA (mRNA); RNA is short for ribonucleic acid (RNA). All known forms of life contain RNA and DNA. They're the genetic instructions, as it were, that determine how lifeforms work and how they develop. Think of them vaguely like blueprints, but with a twist — RNA also helps synthesize proteins and move amino acids. Hence, RNA's role falls somewhere between that of an architect and a barista doling out protein drinks.

There are physical differences between RNA and DNA, but they are beyond the scope of this short explanation. Needless to say, DNA is the "instructions" via which our genes are transferred between us and our offspring. And RNA is in charge of regulating the production of proteins in a body, and its so-called "instructions" that it gives are for cellular structure.

To be clear: RNA and DNA serve different functions, and, as the Centers for Disease Control and Prevention (CDC) explains, mRNA vaccines don't affect or even interact with our DNA at all.

You asked: Where can I get reliable information? I would first direct you to this information published by the CDC. As the CDC explains, mRNA vaccines "teach our cells how to make a protein—or even just a piece of a protein—that triggers an immune response inside our bodies." 

Now, onto the specifics of mRNA, or messenger RNA. Messenger RNA is a single-stranded RNA molecule that provides instructions on protein production. Due to its structure, its existence is short-lived, meaning that once the mRNA is injected in your body, it will shortly disappear once it enters a cell and instructs the cell to produce a copy of a protein called Spike.

Spike is the protein that, true to its name, appears as spikes on the exterior of the spherical coronavirus. In artists' impressions, the sea urchin-like spikes on the virus are Spike proteins.

In other words, mRNA vaccines don't inject our bodies with a piece of the coronavirus; instead, they give instructions on how to produce Spike. Those instructions are delivered via mRNA.

The idea is that if your immune system knows what Spike looks like, and recognizes it as an intruder, it will attack anything that contains Spike — including the novel coronavirus, in the event that it enters your body. 

In other words, the mRNA vaccine doesn't actually inject us with a dead coronavirus, or a piece of the coronavirus hidden in a different virus (as other vaccines do). Rather, it gives us the instructions to make Spike, which our cells then do; our immune system then detects the Spike in our bloodstream and creates antibodies to fight it off and detect it in the future. 

Regarding the question of DNA: this neat little trick does not happen through manipulation of our DNA, but instead through a process of "tricking" our immune system — specifically, by introducing it to a harmless synthetic piece of the Spike protein that is built and deconstructed in our own cells, via instructions in the mRNA.

It's true that mRNA vaccines are a relatively new technology, but as Salon has reported before, it is likely to be the vaccine of the future. That's in part because mRNA vaccines are easier to produce within a shorter period of time, and easier to modify in the future if necessary.

While mRNA vaccine technology is "new," it's important to note that its development has been in the making for nearly 30 years. My colleague Matthew Rozsa interviewed Dr. Katalin Karikó, whose work laid the foundation for the COVID-19 vaccines. His interview is a great read if you're interested in learning more about the history of mRNA vaccines, and how they're different from other vaccines you've probably received in your life.

"Vaccines containing killed viruses or viral proteins will only induce antibodies," Karikó told Salon's Matthew Rozsa. "Meanwhile, mRNA vaccines, in addition to antibodies, also induce cellular immune response," she added, "because the encoded viral proteins are synthesized inside the cell of the vaccinated person."

The falsehood that the "mRNA in the vaccine can adversely affect a person's DNA," which is what your family member believes, isn't true — as it's impossible for mRNA to affect or infect a person's DNA. This is a rumor that has been debunked by multiple scientists — just look here, here, and here.

I agree it's complicated, Confused by mRNA. This is a new kind of a vaccine, and unless you've studied biology, cellular biology or biochemistry, understanding the mechanisms of it can be hard to grasp. I hope this helps, and that your family member will better understand that mRNA vaccines don't affect a person's DNA.

In fact, the mRNA vaccines have been revealed to be safer than the traditional vaccines, at least in the Western World. Both the Johnson & Johnson and AstraZeneca vaccines — which are not mRNA vaccines — have been beset by very rare blood clot issues that have resulted in some countries suspending their usage. The two mRNA vaccines, on the other hand, have seen no "safety signals," as they are called, even after hundreds of millions of shots given.


Pandemic Problems

"Pandemic Problems" is an advice column answering readers' pandemic problems — sometimes with the help of moral philosophy professors and therapists — who can weigh in on how to "do the right thing." Do you have a "pandemic problem"? Email Nicole Karlis at Peace of mind and collective commiseration awaits.

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By Nicole Karlis

Nicole Karlis is a senior writer at Salon, specializing in health and science. Tweet her @nicolekarlis.

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