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Fact Check: No, The mRNA COVID-19 Vaccines Do Not Alter Your DNA


Tom Hale

Tom is a writer in London with a Master's degree in Journalism whose editorial work covers anything from health and the environment to technology and archaeology.

Senior Journalist

COVID-19 vaccine.

Like all approved vaccines, the new generation mRNA vaccines for COVID-19 have undergone rigorous clinical trials. Image credit:

One of the most common rumors about the COVID-19 vaccinations doing the rounds on social media has focused on the fear that the vaccine will somehow alter your DNA. Rest assured, this is not true.

Two of the main COVID-19 vaccines being approved and rolled out Pfizer/BioNTech’s BNT162b2 and Moderna’s mRNA-1273  are mRNA vaccines. They are two of the first vaccines of this kind to receive approval from a medical regulator. 


They work by injecting a small synthetic fragment of the virus's genetic code, the mRNA, into the human body. This genetic code gives instructions for our cells to make a harmless piece of the virus’ “spike protein,” prompting the body’s cells to read these instructions and produce the harmless fragment. Once our immune system encounters this piece of protein, it "learns" to recognize and produce antibodies against it. In a sense, mRNA vaccines provide instructions for our own bodies to actually make the vaccine. This stands in contrast to “conventional” vaccines which achieve a similar effect using weakened versions of the pathogen or a harmless part of the pathogen. 

Some have falsely suggested the systematic genetic material present in mRNA vaccines somehow mixes with our own genetic material and alters it. However, this is false. Although rRNA does enter the human cell and is reproduced by the cells’ own protein making-machinery, it does not enter the nucleus, the hub of cells where our chromosomes are stored.

“Your DNA – your instructions to make you – is contained within the cell, it’s contained in the cell nucleus. This mRNA has no way to actually access this part of the cell,” Helen Petousis-Harris, vaccinologist and Associate Professor in the Department of General Practice and Primary Health Care at the University of Auckland in New Zealand, said in an online briefing in December 2020.

“And the other reason is that if it were to be able to get in there, and actually integrate or do something to our genome, it would need to be something like a retrovirus or something like that, which it’s not. So, there’s actually no biologically plausible way that an RNA vaccine can meddle with your genome," Petousis-Harris continued.


Furthermore, the mRNA doesn’t continuously multiply in your body forever. The fragment of genetic material is relatively fragile and will only hang around inside a cell for about 72 hours after the jab, before being broken down.

Like all vaccines, the new generation mRNA vaccines for COVID-19 that have recently been approved in the UK, the US, Canada, the European Union, and other parts of the world have undergone rigorous testing on tens of thousands of people. Despite being developed in less than a year, numerous peer-reviewed studies and extensive evaluation by medical regulatory authorities have concluded that the vaccines are safe and run an extremely low risk of causing serious side-effects.

"It’s likely to be very, very safe,” added Petousis-Harris, speaking about the mRNA vaccines.


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