“The four factors (to deal with) of vaccines hesitancy. The EClinMed -The Lancet study” is an international study led by Università Cattolica, Campus of Rome, in collaboration with New York Medical College, University of Belgrade and University of Veron which analyzes the contributing factors and proposes possible solutions. Infact, despite high rates of vaccination being required worldwide to establish a herd immunity and stop the current COVID-19 pandemic evolution, vaccine hesitancy has been revealed as a major barrier across different populations. Listen to the voice of Fidelia Cascini, Assistant Professor of Hygiene and Public Health at Università Cattolica, Campus of Rome.