As COVID-19 vaccines are authorized and then recommended for use in the United States, it will be important to understand what is known about each vaccine. CDC will provide information on who is and is not recommended to receive each vaccine and what to expect after vaccination, as well as ingredients, safety, and effectiveness.
There are two COVID-19 vaccines currently authorized and recommended for use in the United States, and three other vaccines are currently in large-scale clinical trials.
COVID-19 mRNA vaccines teach our cells how to make a piece of a protein to trigger an immune response and build immunity to the virus that causes COVID-19. mRNA does not affect or interact with a person’s DNA, and the cell breaks down and gets rid of the mRNA as soon as it is finished using these instructions.