COVID-19 is the illness that’s caused by the novel coronavirus SARS-CoV-2. To date, the Food and Drug Administration (FDA) has provided emergency use authorization to three different vaccines to help protect against COVID-19. The vaccines that have been authorized for emergency use in the United States so far use two different types of technology: Messenger RNA (mRNA) and adenovirus vector. Let’s break down how each vaccine uses one of these two technologies to help promote immunity against the coronavirus. The included infographic provides a visual representation of how the mRNA and adenovirus vector vaccines work.