Vaccine effectiveness against infection and onwards transmission of COVID-19: Analysis of Belgian contact tracing data, January-June 2021., Braeye, Toon, Cornelissen Laura, Catteau Lucy, Haarhuis Freek, Proesmans Kristiaan, De Ridder Karin, Djiena Achille, Mahieu Romain, De Leeuw Frances, Dreuw Alex, et al. , Vaccine, 2021 09 15, Volume 39, Issue 39, (2021)