Virus Outbreak AstraZeneca

FILE - In this Sunday, March 21, 2021 file photo a man receives a COVID-19 vaccine at a vaccination center in Belgrade, Serbia. Serbia has vaccinated most people with China's Sinopharm jabs, followed by Pfizer, Russia's Sputnik V and recently the AstraZeneca shot. AstraZeneca said Monday March 22, 2021 that advanced trial data from a U.S. study on its COVID vaccine shows it is 79% effective. The U.S. study comprised 30,000 volunteers, 20,000 of whom were given the vaccine while the rest got dummy shots. (AP Photo/Darko Vojinovic)