COVID-19 is detected directly by identifying SARS-CoV-2 RNA with a nucleic acid amplification test or indirectly by identifying viral proteins with an antigen test. COVID-19 vaccine development focused on the protein found in SARS-CoV-2. The COVID-19 vaccines are mRNA vaccines which introduce mRNA corresponding to the viral protein found on the outer membrane of the virus. Cells use the mRNA to produce viral protein which is recognized by the immune system. Once educated, the immune system generates antibodies which recognize the virus. These antibodies remain in the body so the immune system can quickly activate if exposed to the virus again.