Development of an effective immune response in adults with Down Syndrome after SARS-CoV-2 vaccination.

ABSTRACT

BACKGROUND: Immune dysregulation in individuals with Down syndrome (DS) leads to an increased risk for hospitalization and death due to COVID-19 and may impair the generation of protective immunity after vaccine administration. METHODS: The cellular and humoral responses of 55 DS patients who received a complete SARS-CoV-2 vaccination regime at one to three (V1) and six (V2) months were characterized. RESULTS: SARS-CoV-2-reactive CD4 + and CD8+ T lymphocytes with a predominant Th1 phenotype were observed at V1 and increased at V2. Likewise, an increase of SARS-CoV-2-specific circulating Tfh (cTfh) cells and CD8+ CXCR5+ PD-1hi lymphocytes were already observed at V1 after vaccine administration. Specific IgG antibodies against SARS-CoV-2 S protein were detected in 96% and 98% of subjects at V1 and V2, respectively, though IgG titers decreased significantly between both timepoints. CONCLUSIONS: Our findings show that DS individuals develop an effective immune response to usual regimes of SARS-CoV-2 vaccination.