Viral vector vaccines do not turn you transgenic or modify your genome

You have sent us a video whose protagonist is a woman who identifies herself as Chinda Brandolino, and who is giving a talk in front of the camera and with microphone in hand. She makes some arguments against covid-19 vaccination, specifically mentioning viral vector vaccines (such as those of AstraZeneca or Janssen). In her opinion, these injections "modify the genome", making "that vaccinated person a transgenic, transhuman person". This is FALSE. Viral vector vaccines are not capable of modifying a person's genome. 

"When you, with an adenovirus vaccine, modify the genome, that vaccinated person is a transgenic, transhuman person".

Brandolino is a well-known personality in the world of disinformation in Latin America. She started to become relevant in 2018 in Argentina, when she publicly showed her rejection to abortion in the Argentinean Senate. With the arrival of the pandemic, she moved from abortion to vaccines, about which she has given talks, conferences and speeches. In them, she claims that the virus was created in a laboratory, and that vaccines are absolutely useless, both claims lacking any scientific basis, as we have explained here and here. The Argentine verification agency Chequeado has investigated her track record as a disseminator of disinformation. 

A transgenic person?

In one of her latest speeches, Brandolino claims that adenovirus vaccines "modify the genome" and that people who receive them become "transgenic, transvaccinated". 

The Royal Spanish Academy defines transgenic as "said of a living organism, which has been modified by the addition of exogenous genes to achieve new properties". Is that what vaccines could turn us into? It doesn't seem so: according to scientific evidence, it is not possible to modify the genome of a cell by introducing the DNA fragment of the virus into the nucleus of human cells, basically because it "does not integrate" into the DNA of the cell. This is confirmed by the US Centers for Disease Control and Prevention (CDC). At Verificat we already denied this some time ago.

How do these vaccines really work? 

Adenovirus vaccines, known as viral vector vaccines ( since they use another virus as a vehicle or vector for genetic material), contain DNA fragments with instructions to produce an antigen —a substance that induces an immune response when introduced into the body—. The covid-19 vaccine antigen in particular is the famous S protein, an element that will help the immune system identify SARS-CoV-2 if the vaccinated person becomes infected in the future. 

Hence, the most characteristic feature of viral vector vaccines compared to other types of vaccines, such as mRNA or protein subunit vaccines, is the capsid containing the genetic material. Covid-19 vaccines use an adenovirus, a type of virus that, unlike others such as HIV, does not have the enzymatic machinery needed to integrate its DNA into human cells. To complicate matters, the adenoviruses used in the manufacture of AstraZeneca and Janssen's vaccines are created from cell lines that, according to the Food and Drug Administration (FDA), are completely “non-integrating”. In other words, they cannot be incorporated into the host genome. 

In other words, the viral DNA serves as an instruction manual for the human mRNA to copy the part that tells it how to make the Spike protein: "Once the piece of protein is made, the cell breaks down the instructions and gets rid of them," explains PAHO in this document.