Fact check: Genetic materials from mRNA vaccines do not multiply in your body forever

Reuters Fact Check. REUTERS

A video shared online in which a man discusses mRNA vaccines includes numerous false claims, including that the vaccines become part of recipients’ bodies, that they alter DNA, and that they haven’t been tested.

The video begins with a man describing how the new vaccines used to protect against COVID-19 are different from vaccines that have been released before (here Timestamp 5.18). Both the Pfizer and Moderna vaccines that are available in the UK are mRNA vaccines.

The man says of the new vaccines: “Once you get this COVID-19 vaccine, and this little bit of genetic material, it becomes part of you. And those cells in your body will start multiplying and you will have parts of the genetic material of a foreign entity in your body for the rest of your life, there’s nothing that you can do about it. It now becomes part of you. You have been genetically engineered. Your DNA is now different from what it was prior to getting the vaccine.” (Timestamp 7.47)

Reuters has previously debunked claims that mRNA vaccines alter recipients’ DNA (here) While these types of vaccines do involve the injection of a small part of the virus’s genetic code to stimulate immune response in a patient without an infection (here) in contrast to the more widespread “conventional” vaccines (here) which use a whole pathogen or fragment, the mRNA from the vaccine does not alter the recipient’s DNA, is broken down shortly after vaccination and does not stay in the body (here).

The man in the video also says that when a vaccine recipient comes into contact with the full virus in the environment, the person’s immune system will overreact and a “total immune response will take place” in every area in which the virus’s genetic material has been incorporated. “You will perish in about 4 or five days with sepsis,” he says (Timestamp 8.36). The man also claims that the vaccine had not been tested on human beings yet (Timestamp 10.13). Both claims are false.

Tens of thousands of human test participants have received the Pfizer vaccine (here) and the Moderna vaccine (here ), both of which have been deemed to be safe by the UK medicine regulators (here).


False. Vaccines using mRNA do not permanently stay in a recipient’s body or alter DNA. The COVID-19 vaccines available in the UK have been tested on human volunteers and found to be safe.

This article was produced by the Reuters Fact Check team. Read more about our work to fact-check social media posts  here .