evidence: Both the Pfizer and Moderna vaccines are mRNA vaccines, which contain tiny fragments of the genetic material known as "messenger ribonucleic acid". And if social media is anything to go by, some people are concerned these vaccines can affect their genetic code. [...] Your genetic code is made up of a different, but related, molecule to the vaccine mRNA, known as DNA, or deoxyribonucleic acid. And mRNA can’t insert itself into your DNA for two reasons.