Vaccine effectiveness against onward transmission of SARS-CoV2-infection by variant of concern and time since vaccination, Belgian contact tracing, 2021., Braeye, Toon, Catteau Lucy, Brondeel Ruben, Van Loenhout Joris, Proesmans Kristiaan, Cornelissen Laura, Van Oyen Herman, Stouten Veerle, Hubin Pierre, Billuart Matthieu, et al. , Vaccine, 2022 May 11, Volume 40, Issue 22, (2022)