Factor associated with SARS-CoV-2 vaccination serological efficacy in adolescents and adults with Down syndrome: data from an international, collaborative initiative of the Trisomy 21 Research SocietyRUNNING TITLE: Factors determining COVID-19 vaccine efficacy in Down syndrome - Valentini D; Carfi A; Di Paola A; Yarci-Carrión A; Villani A; Real de Asúa D (Journal Of Infection, 2023)