[This corrects the article DOI: 10.3389/fimmu.2022.873067.].
Keywords: BCG; COVID-19; SARS-CoV-2; elderly vaccination; trained immunity.
Copyright © 2022 Tsilika, Taks, Dolianitis, Kotsaki, Leventogiannis, Damoulari, Kostoula, Paneta, Adamis, Papanikolaou, Stamatelopoulos, Bolanou, Katsaros, Delavinia, Perdios, Pandi, Tsiakos, Proios, Kalogianni, Delis, Skliros, Akinosoglou, Perdikouli, Poulakou, Milionis, Athanassopoulou, Kalpaki, Efstratiou, Perraki, Papadopoulos, Netea and Giamarellos-Bourboulis.