It's been like dominos: One European nation after the other has put a pause on AstraZeneca shots due to unproven concerns that the coronavirus vaccine may cause blood clots. POLITICO Europe's Sarah Wheaton breaks down how and why countries panicked despite a lack of evidence. Sarah Wheaton is POLITICO Europe's chief policy correspondent. Jeremy Siegel is a host for POLITICO Dispatch and produces Pulse Check. Jenny Ament is the senior producer of POLITICO Audio. Irene Noguchi is the executive producer of POLITICO Audio.