AZD1222, formerly known as ChAdOx1 nCoV-19, is being developed by the University of Oxford and AstraZeneca plc (AZN).Current Status: AZD1222 is under a phase III trial in healthy adults aged 18 to 55 years in Brazil.Mode of Action: AZD1222 uses a replication-deficient chimpanzee viral vector based on a weakened version of a common cold (adenovirus) virus that causes infections in chimpanzees and contains the genetic material of SARS-CoV-2 spike protein. Following vaccination, the surface spike protein is produced, stimulating the immune system to attack COVID-19 if it later infects the body.Next Milestone: Completion of phase III trial by July 2021.