BNT, or BNT162b2, is a messenger RNA (mRNA) vaccine developed by BioNTech and Pfizer to protect against the COVID-19 virus. It works by instructing cells to produce a harmless piece of the virus's spike protein, prompting the immune system to recognize and fight the virus if exposed in the future. The vaccine has been shown to be effective in preventing severe illness and hospitalization caused by SARS-CoV-2, the virus responsible for COVID-19. It has received emergency use authorization in many countries and is a key tool in global vaccination efforts to control the pandemic.