3-MIN READ How Oxford Scientists Developed AstraZeneca s Covishield Vaccine in Record Time A vial of the COVID-19 vaccine developed by Oxford University and U.K.-based drugmaker AstraZeneca is checked. (Gareth Fuller/Pool via AP) ChAdOx1 as it can generate a strong immune response and is not a replicating virus, so it cannot cause an infection. It had already been used safely in thousands of subjects in clinical trials of vaccines for other diseases including Middle Eastern respiratory syndrome (MERS), which is caused by another type of coronavirus. FOLLOW US ON: As the world s largest vaccination drive is about to start in India on Saturday, one of the two vaccines approved so far has been Oxford-AstraZeneca s Covishield.