At the end of 2020, the vaccine rollout was chaotic: appointments were hard to schedule, vaccine supplies were tight, and the U.S. had administered fewer than 3 million doses over several weeks. But today, things have dramatically improved. CNN’s Chief Medical Correspondent Dr. Sanjay Gupta speaks with Claire Hannan, Executive Director of the Association of Immunization Managers, about how the U.S. turned its vaccine rollout around.To learn more about how CNN protects listener privacy, visit cnn.com/privacy