Factors underlying COVID-19 booster vaccine uptake among fully vaccinated adults in Belgium, Vermeiren, Elias, Hubin Pierre, Nasiadka Léonore, Stouten Veerle, Billuart Matthieu, Van Evercooren Izaak, Catteau Lucy, and Van Loenhout Joris , Scientific Seminar Infectious Diseases, 11/05/2023, Brussels, Belgium, (2023)