mRNA vaccines, which are what the Pfizer and Moderna vaccines are built on, ​safely teach our cells how to make a protein that ​in turn teaches your body how to make an antibody that fights the virus that causes COVID-19. This is what protects us from getting infected if the real virus enters our bodies.

Specifically, COVID-19 mRNA vaccines give instructions for our cells to make a harmless piece of what is called the “spike protein.” The spike protein is found on the surface of the virus that causes COVID-19. Once a person receives the vaccine, the instructions (mRNA) are inside the muscle cells and the cells use them to make the protein piece. After the protein piece is made, the cell breaks down the instructions and gets rid of them. It does not alter or interact with your DNA in any way.

Our immune systems recognize that the protein doesn’t belong there and begins making antibodies, like what happens in natural infection against COVID-19. The benefit of mRNA vaccines, like all vaccines, is those vaccinated gain this protection without ever having to risk the serious consequences of getting sick with COVID-19.

Read this Infographic from the CDC on How mRNA COVID-19 Vaccines Work.

The J&J vaccine uses a viral vector (or virus-based platform) to protect you. Learn more about this in this CDC Infographic on How Viral Vector COVID-19 Vaccines Work.