Vaccination Hesitancy among Health-Care-Workers in Academic Hospitals Is Associated with a 12-Fold Increase in the Risk of COVID-19 Infection: A Nine-Month Greek Cohort Study oleh Fotinie Ntziora, Evangelia Georgia Kostaki, Ioannis Grigoropoulos, Amalia Karapanou, Ismini Kliani, Maria Mylona, Alexa Thomollari, Sotirios Tsiodras, Theoklis Zaoutis, Dimitrios Paraskevis, Nikolaos V. Sipsas, Anastasia Antoniadou, Petros P. Sfikakis