Vaccines will prepare the human body to defend against COVID-19. To enter the body and cause disease, the SARS-CoV-2 virus uses a protein on its shell, a protein called protein S (spike). Vaccines contain the genetic instructions (messenger RNA) needed to generate the S protein. When a person is vaccinated, their cells will "read" the genetic instructions in the messenger RNA and synthesize the S protein. The person's immune system will recognize this protein as and will trigger immune defense mechanisms, producing specific antibodies and T cells. If the vaccinated person later comes into contact with the SARS-CoV-2 virus, their immune system will recognize the virus and, through specific antibodies and T cells, will neutralize the virus, thus preventingentering healthy cells of the body and destroying any infected cells. This will ensure protection against COVID-19.