Fact check: Do the mRNA COVID vaccines act as 'gene therapy?'
Posted September 20, 2021 1:48 p.m. EDT
Updated September 20, 2021 4:39 p.m. EDT
Joe Rogan, who hosts one of the most popular podcasts on Spotify, wrongly claimed that the Pfizer and Moderna COVID-19 vaccines are "really gene therapy," conflating the vaccines’ pioneering mRNA technology with the experimental technique that involves modifying genes to treat or cure disease.
The inaccurate claim came about 51 minutes into the Aug. 20 episode of "The Joe Rogan Experience" as Rogan discussed the vaccines with guest Meghan Murphy, a Canadian freelance writer and journalist.
Here’s what Rogan said:
"It's not really a vaccine in the traditional sense. A vaccine is where they take a dead virus, and they turn it into a vaccine, and they inject it into your body so that your body fights off — it develops the antibodies, and your body understands what that is, whether it's the measles or polio, it knows how to fight it off.
"This is really gene therapy. It's a different thing. It’s tricking your body into producing spike protein and making these antibodies for COVID. But it’s only good for a few months, they’re finding out now. The efficacy wanes after five or six months. I’m not saying that people shouldn’t take it. But I’m saying, you’re calling it a thing that it’s not. It’s not exactly what you’re saying it is, and you’re mandating people take it."
There’s no national mandate requiring that all Americans get vaccinated against COVID-19, although many employers and university systems are requiring it. And Rogan based his claim about the COVID-19 vaccines partly on an outdated conception of what a vaccine is.
But the bigger problem with the claim is that it mischaracterizes the technology used by the Pfizer and Moderna vaccines. The technology does not amount to gene therapy, public health experts said.
"It's absolutely incorrect to say that vaccines are really gene therapy," said Cindy Prins, clinical associate professor of epidemiology at the University of Florida. "Vaccines don't make any changes to your own DNA, so they don't edit your own DNA like gene therapy does. They also don't replace any mutated genes in your body."
No genetic material enters the part of the cell that hosts DNA as a result of the mRNA vaccines.
Rogan and Spotify did not offer on-the-record comments for this fact-check.
How the mRNA COVID-19 vaccines work
The Centers for Disease Control and Prevention defines a vaccine as "a product that stimulates a person’s immune system to produce immunity to a specific disease."
"Basically, a vaccine is a way to get your immune system to recognize something and create antibodies to it," said Richard Watanabe, professor of population and public health sciences at the University of Southern California.
The Pfizer and Moderna vaccines fit that definition, the CDC says. While they work differently than many other familiar vaccines — relying on messenger RNA, or mRNA, technology — they still trigger an immune response inside the body, offering vital protection.
Older methods of vaccination included inoculating people with inactivated versions of viruses, and some vaccines for other diseases still work that way. But that method has proven at times to be risky, Watanabe said, citing the infamous "Cutter Incident" of 1955, in which some polio vaccines were not properly inactivated and tens of thousands of people were accidentally injected with the live virus.
The mRNA technology in the Pfizer and Moderna COVID-19 vaccines is newer, though research on it dates back to the 1990s.
The vaccines work by instructing the cells to make versions of a harmless spike protein found on the surface of the coronavirus, so the immune system can recognize the protein and mount an antibody response against the virus in the event of a future infection, the CDC says.
The third COVID-19 vaccine available in the U.S., from Johnson & Johnson, delivers similar instructions using an adenovirus that’s been altered to make it harmless.
"It’s true that mRNA vaccines are a major departure from traditional vaccines," said Dr. Amesh Adalja, a senior scholar at the Johns Hopkins Center for Health Security. "They contain just the genetic material of the gene of interest in the pathogen that codes for the protein needed for immunity. That’s what makes them so path-breaking."
The mRNA vaccine technology isn’t ‘really gene therapy’
While both mRNA vaccination and gene therapy involve genetic technology, they are different things, experts said.
Gene therapy involves modifying a person’s genes to cure or treat a disease, according to the Food and Drug Administration. The FDA says it can work by replacing a disease-causing gene in the body with a healthy version, turning off the disease-causing gene, or introducing a new gene entirely. Only a few gene therapies have been fully approved, said Prins.
"Gene therapy is used to replace or fix genetic mutations that lead to diseases like cystic fibrosis, neuromuscular disease, inherited blindness and other genetic conditions," Prins said. "Gene therapy is not used in vaccines at all, since vaccines don't replace or edit your own genes."
Gene therapy corrects a genetic defect by delivering the gene, or DNA, to the nucleus, the part of the cell where DNA is located, Adalja said.
The mRNA COVID-19 vaccines are designed around the genetic structure of the virus. They carry mRNA, which teaches the immune system to identify the coronavirus, but they do not alter the recipients’ genetic makeup or DNA. The mRNA strands never enter the nucleus of the cell after vaccination.
To cross into the nucleus, the mRNA chains from the shots would need a special enzyme, according to WebMD. And they would need another enzyme to be integrated into the DNA. They don’t have those enzymes.
"It’s really just a different approach to delivering what the immune system needs to see in order to create the antibodies," Watanabe said of the mRNA vaccines.
The mRNA strands also break down shortly after entering the body, unlike with gene therapy, Prins said.
"It sticks around in the cell only long enough to be used as a recipe to make some spike protein that the immune system can then detect and respond to," Prins said. "After a few days, your cells will break up that mRNA into small pieces. So the recipe gets torn up. The spike protein that was made will stay around a little longer, up to a few weeks, which helps you build that immune response. But it will also get broken down so it doesn't stay for long."
Moderna says on its website that while mRNA and gene therapy might sound similar, they "take fundamentally different approaches." The company wrote:
"Gene therapy and gene editing alter the original genetic information each cell carries. The goal is to produce a permanent fix to the underlying genetic problem by changing the defective gene ... Unlike gene editing and gene therapy, mRNA technology does not change the genetic information of the cell, and is intended to be short-acting."
In the same podcast episode, Rogan claimed that "it’s not supported by science" for people who have previously been sick with COVID-19 to get the shots. But public health experts recommend that people who have had COVID-19 already get immunized anyway, because the science shows they provide better and broader protection than natural immunity.
Rogan said the mRNA COVID-19 vaccines are "really gene therapy."
That’s wrong. The two interventions are not the same. Gene therapy involves modifying genes to cure or treat a disease.
The COVID-19 vaccines from Pfizer and Moderna use mRNA technology to instruct the cells to recognize a spike protein on the coronavirus and mount a response against it, but they make no changes to the recipient’s genetic makeup or DNA. The mRNA strands never enter the part of the cell that hosts DNA, and they are broken down soon after they are introduced into the body.
We rate Rogan’s claim False.