A main event and multiple introductions of SARS-Cov2 initiated the COVID-19 epidemic in Greece.

Spanakis, Nikolaos; Kassela, Katerina; Dovrolis, Nikolas; Bampali, Maria; Gatzidou, Elisavet; Kafasi, Athanasia; Froukala, Elisavet; Stavropoulou, Anastasia; Lilakos, Konstantinos; Veletza, Stavroula; Tsiodras, Sotirios; Tsakris, Athanasios; Karakasiliotis, Ioannis

SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) is a novel Coronavirus responsible for the Coronavirus Disease-2019 (COVID-19) pandemic. Chains of infections starting from various countries worldwide seeded the outbreak of COVID-19 in Athens, capital city of Greece. Full-genome analysis of isolates from Athens' hospitals and other healthcare providers revealed the variety of SARS-CoV-2 that initiated the pandemic before lock-down and passenger flight restrictions. A dominant variant, encompassing the G614D amino acid substitution, spread through a major virus dispersal event and sporadic introductions of rare variants characterised the local initiation of the epidemic. Mutations within the genome highlighted the genetic drift of the virus as rare variants emerged. An important variant encompassed a premature stop codon in orf7a leading to the truncation of a possibly important for viral pathogenesis domain. The present work may serve as reference for resolving future lines of infection in the area especially after resumption of passenger flight connections to Athens and Greece during summer of 2020. This article is protected by copyright. All rights reserved.