mRNA stands for messenger ribonucleic acid and can be described as ‘instructions for how to make a protein or even just a piece of a protein’. mRNA is not able to The mRNA from a COVID-19 vaccine never enter the nucleus of the cell, which is where our DNA are kept and therefore cannot alter or modify a person’s genetic makeup (DNA). Instead, COVID-19 vaccines that use mRNA work with the body’s natural defences to safely develop protection (immunity) to disease.