SARS-CoV-2 Sero-Surveillance in Greece: Evolution over Time and Epidemiological Attributes during the Pre-Vaccination Pandemic Era oleh Michalis Koureas, Zacharoula Bogogiannidou, Alexandros Vontas, Maria A. Kyritsi, Varvara A. Mouchtouri, Katerina Dadouli, Lemonia Anagnostopoulos, Paraskevi Mina, Alexia Matziri, Maria Ntouska, Maria Tsigaridaki, Vasiliki Gkiata, Konstantinos K. Tsilidis, Evangelia E. Ntzani, Panagiotis Prezerakos, Sotirios Tsiodras, Matthaios Speletas, Christos Hadjichristodoulou