Efstathia Kambissiouli, left, a Greek nurse working in a state hospital intensive care, receives an injection with a dose of COVID-19 vaccine, in Athens, Sunday, Dec. 27, 2020. Kambissiouli was the first person to be vaccinated against coronavirus in Greece, followed a few minutes later by Michalis Giovanidis, a nursing home resident. (AP Photo/Yorgos Karahalis, Pool)