Messenger RNA (mRNA) vaccine

An mRNA vaccine gives cells instructions for how to make the S protein found on the surface of the COVID-19 virus.

The vaccine shot sends the mRNA into the muscle. Your muscle cells may take in the mRNA and make the S protein. Or the mRNA may be picked up by an immune cell. Either the mRNA or the S protein alerts the body to the risk of the virus. Then the body begins to create a response to prevent you from getting sick from the infection.