COVID-19 vaccine uptake among healthcare workers: a systematic review and meta-analysis - Galanis, Petros; Vraka, Irene; Katsiroumpa, Aglaia; Siskou, Olga; Konstantakopoulou, Olympia; Katsoulas, Theodoros; Mariolis-Sapsakos, Theodoros; Kaitelidou, Daphne (Vaccines, 2022)