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Ciara O'Rourke
By Ciara O'Rourke April 14, 2021

No, Moderna’s chief medical officer didn’t say mRNA alters DNA

If Your Time is short

  • Messenger RNA vaccines do not alter DNA.
  • In 2017, Moderna’s chief medical officer gave a TED Talk about mRNA and discussed the potential for an mRNA vaccine against the flu. But he didn’t say such vaccines alter DNA.

"Moderna chief medical officer admits: mRNA alters DNA," reads the description of a video in a Facebook post that’s being shared widely. 

The footage in the video is from a 2017 TED Talk featuring Tal Zaks, chief medical officer of Moderna, which has created an mRNA vaccine against COVID-19 that’s being used across the country. But the Facebook post misrepresents the actual title of the talk and what Zaks said during the event. 

COVID-19 mRNA vaccines do not affect our DNA.

This post was flagged as part of Facebook’s efforts to combat false news and misinformation on its News Feed. (Read more about our partnership with Facebook.)

At the start of the approximately 10-minute presentation, titled "The disease-eradicating potential of gene editing," Zaks said "we’re actually hacking the software of life" in how we prevent and treat disease. 

He then briefly explains how mRNA works. 

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"Our body is made out of organs, our organs are made out of cells, and in every cell there’s this thing called messenger RNA or mRNA for short that transmits the critical information from the DNA — our genes — to the protein, which is really the stuff we’re all made out of. This is the critical information that determines what a cell would actually do."

He compares the whole thing to an operating system, and then says, "and if you could actually introduce a line of code, or change a line of code, it turns out that has profound implications for everything from the flu to cancer." 

But he’s not talking about altering DNA. He uses the flu vaccine as an example. A vaccine is an injection where we get "bits and pieces of the virus, the proteins, and that teaches our immune system to recognize the virus," he said. "Now imagine if instead of giving the protein, we would give the instructions on how to make the protein — how the body can make its own vaccine. That’s an mRNA vaccine."

He then shows two images. One represents a traditional vaccine, where the virus proteins are floating around the cell. The second shows what looks like an mRNA vaccine triggering the cells to create those proteins. 

But mRNA vaccines never enter the nucleus of the cell, which is where our DNA is kept, the Centers for Disease Control and Prevention notes on a page on its site dedicated to understanding mRNA vaccines against COVID-19. After the mRNA triggers the cells to create the virus proteins, the cell then breaks down and gets rid of the mRNA, according to the CDC. 

We’ve previously debunked claims that these vaccines will alter the DNA of those injected. But that’s wrong, and so is the claim that Moderna’s chief medical officer said as much. 

We rate this post False. 


Our Sources

Facebook post, April 13, 2021

Moderna, Moderna’s executive committee, visited April 14, 2021

TED, The disease-eradicating potential of gene editing, November 2017

Centers for Disease Control and Prevention, Moderna COVID-19 vaccine overview and safety, updated April 5, 2021 

Centers for Disease Control and Prevention, Understanding mRNA COVID-19 vaccines, updated March 4, 2021

PolitiFact, No, COVID-19 vaccines won’t alter your DNA and control you, Nov. 18, 2020

PolitiFact, Blog post wrong on what Bill Gates said about COVID-19 vaccine, May 20, 2020


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No, Moderna’s chief medical officer didn’t say mRNA alters DNA

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