The AstraZeneca COVID-19 Vaccine is a viral vector vaccine developed to protect against the COVID-19 virus. It uses a modified version of a common cold virus (adenovirus) from chimpanzees, which has been altered to carry genetic material from the SARS-CoV-2 virus. This helps the body recognize and fight the virus if exposed in the future. The vaccine is administered in two doses, typically given 4 to 12 weeks apart. Clinical trials have shown it to be effective in reducing the risk of severe illness, hospitalization, and death caused by COVID-19. It is widely used in many countries and is part of global vaccination efforts.