My wife who works at an assisted living care facility has obtained the first shot of the vaccine. She told me that the instructions from the state clearly indicate that Pfizer and Moderna are both Messenger RNA (mRNA) vaccines. mRNA are molecules that provide instruction. They do not contain a virus that causes COVID-19. mRNA vaccines teach our cells to create an immune response so that the body knows how to fight with the virus if it is later exposed to the virus. Once your body learns how to create the immune response, it breaks down and gets rid of the mRNA.