COVID-19 Clusters in Belgian Nursing Homes: Impact of Facility Characteristics and Vaccination on Cluster Occurrence, Duration and Severity, Dequeker, Sara, Callies Milena, Catteau Lucy, Int Panis Laura, Islamaj Esma, Klamer Sofieke, Latour Katrien, Pauwels Marijke, Vernemmen Catharina, Mahieu Romain, et al. , Viruses, Jan-01-2023, Volume 15, Issue 1, (2023)