Vaccines that use mRNA technology are not gene therapy because they do not alter your genes, experts have told Reuters after contrary claims were posted online.
Thousands of social media users have shared such posts since the rollout of COVID-19 vaccines began (here) – and have continued to do so through August.
Pfizer/BioNTech and Moderna have both developed shots that use a piece of genetic code from SARS-CoV-2, the coronavirus that causes COVID-19, to prompt an immune response in recipients (here). However, experts told Reuters that this is not the same as gene therapy.
“As mRNA is genetic material, mRNA vaccines can be looked at as a genetic-based therapy, but they are classified as vaccines and are not designed to alter your genes,” said Dr Adam Taylor, a virologist and research fellow at the Menzies Health Institute, Queensland, Griffith University.
“Gene therapy, in the classical sense, involves making deliberate changes to a patient’s DNA in order to treat or cure them. mRNA vaccines will not enter a cell’s nucleus that houses your DNA genome. There is zero risk of these vaccines integrating into our own genome or altering our genetic makeup.”
Taylor explained that mRNA enters cells shortly after vaccination and instructs them to create a SARS-CoV-2 spike protein, prompting the immune response.
He added that unlike gene therapy, mRNA vaccines are then “rapidly degraded” by the body.
“In fact, because mRNA is degraded so quickly chemical modifications can be made to mRNA vaccines to make them a little more stable than regular mRNA.”
Gene therapy, on the other hand, involves a process whereby an individual’s genetic makeup is deliberately modified to cure or treat a specific genetic condition (here).
It can be done in several ways, such as replacing a disease-causing gene with a healthy alternative, disabling a disease-causing gene or introducing a new gene to help treat a disease, according to the U.S. Food and Drug Administration (FDA) (here).
“If we suffer from an inherited blood disease then the defect in our genes can be corrected in blood cells and then we can be cured,” said David Schaffer, professor of Chemical and Biomolecular Engineering and Director of the Berkeley Stem Cell Center at the University of California, Berkeley, in an email to Reuters.
“In most cases, the DNA is therapeutic because it encodes a mRNA, which encodes a protein that has a beneficial effect on a patient. So, if someone has a disease where the gene encoding an important protein is mutated - such as hemophilia, cystic fibrosis, retinitis pigments - then it can be possible to deliver the DNA encoding the correct copy of that protein in order to treat the disease.”
He added: “Because DNA has the potential to persist in the cells of a patient for years, this raises the possibility of a single gene therapy treatment resulting in years of therapeutic benefit.”
Moderna, which has developed one of the mRNA COVID-19 vaccines used across the world, explained in a fact sheet that mRNA and gene therapy take “fundamentally different” approaches.
“Gene therapy and gene editing alter the original genetic information each cell carries,” the company writes. “The goal is to produce a permanent fix to the underlying genetic problem by changing the defective gene. Moderna is taking a different approach to address the underlying cause of MMA and other diseases. mRNA transfers the instructions stored in DNA to make the proteins required in every living cell. Our approach aims to help the body make its own missing or defective protein” (www.modernatx.com/about-mrna).
Missing context. Scientists told Reuters that while mRNA vaccines can be considered “genetic-based therapy” because they use genetic code from COVID-19, they are not technically gene therapy. This is because the mRNA does not change the body’s genetic makeup.
This article was produced by the Reuters Fact Check team. Read more about our work to fact-check social media posts here .