The Pfizer Vaccine, officially known as the Pfizer-BioNTech COVID-19 vaccine, is an mRNA vaccine designed to protect against the COVID-19 virus. It works by teaching the immune system to recognize and fight the virus if exposed. The vaccine is administered in two doses, typically three weeks apart, and has been shown to be effective in reducing the risk of severe illness and hospitalization. The Pfizer Vaccine received emergency use authorization from health authorities, including the U.S. Food and Drug Administration (FDA), in late 2020. Clinical trials demonstrated its safety and efficacy, leading to widespread distribution and vaccination efforts globally.