Head of the Police Medical Service shows a vial of AstraZeneca vaccine during the start on the vaccination campaign for police officers, in Hanover, Germany, March 4, 2021. A shipment of a quarter million AstraZeneca vaccines destined for Australia has been barred from leaving the European Union in the first use of an export control system instituted by the bloc over a month ago. An EU official, who asked not to be identified because of the sensitivity of the issue, confirmed a report that first