A growing number of European nations are suspending use of the AstraZeneca COVID vaccine, one of three on the continent, after reports of blood clots and other problems among a small number of people. AstraZeneca says these are isolated cases. Dr. Kirsten Bibbins-Domingo, chair of epidemiology and biostatistics at the University of California, San Francisco, joins William Brangham to discuss. PBS NewsHour is supported by - https://www.pbs.org/newshour/about/funders