Messenger RNA, or mRNA, vaccines work by introducing a strand of messenger RNA into your body. Messenger RNA is used to build proteins, and the mRNA in this vaccine contains instructions that teach your immune system how to create a specific type of protein known as a "spike protein." This spike protein is found on the surface of the coronavirus that causes Covid-19. The coronavirus uses this spike protein to get into your cells and cause infection. This protein itself is harmless to us, but our immune system recognizes it as foreign and therefore wants to destroy it. The immune system begins to develop specific antibodies that it can use to destroy the newly introduced mRNA. That way, if you get infected with the coronavirus, your body will recognize the spike protein and will be able to fight it more effectively since it will have learned how to fight it before. The vaccine does not alter your DNA in any way, and it does not contain any actual virus.