ABSTRACT
To guide evidence-based prevention of COVID-19 in children, we estimated risks of severe outcomes in 820,404 symptomatic paediatric cases reported by 10 EU Member States between August 2020 and October 2021. Case and hospitalisation rates rose as overall transmission increased but severe outcomes were rare: 9,611 (1.2%) were hospitalised, 640 (0.08%) required intensive care and 84 (0.01%) died. Despite increased individual risk (aOR; 95% CI for hospitalisation: 7.3; 3.3 - 16.2, ICU: 8.7; 6.2 - 12.3) in cases with comorbidities such as cancer, diabetes, cardiac or lung disease, most (83.7%) hospitalised children had no reported comorbidity.
Subject(s)
COVID-19 , Diabetes Mellitus , Neoplasms , Lung DiseasesABSTRACT
AZD1222 (ChAdOx1 nCoV-19), a replication-deficient simian adenovirus-vectored vaccine, has demonstrated safety, efficacy, and immunogenicity against coronavirus disease 2019 (COVID-19) in clinical trials and real-world studies. We characterized CD4+ and CD8+ T-cell responses induced by AZD1222 vaccination in peripheral blood mononuclear cells (PBMCs) from 280 unique vaccine recipients aged 18-85 years who enrolled in the phase 2/3 COV002 trial. Total spike-specific CD4+ T cell helper type 1 (Th1) and CD8+ T-cell responses were significantly increased in AZD1222-vaccinated adults of all ages following two doses of AZD1222. CD4+ Th2 responses following AZD1222 vaccination were not detected. Furthermore, AZD1222-specific Th1 and CD8+ T cells both displayed a high degree of polyfunctionality in all adult age groups. T-cell receptor (TCR) {beta} ; sequences from vaccinated participants mapped against TCR sequences known to react to SARS-CoV-2 revealed substantial breadth and depth across the SARS-CoV-2 spike protein for the AZD1222-induced CD4+ and CD8+ T-cell responses. Overall, AZD1222 vaccination induced a robust, polyfunctional Th1-dominated T-cell response, with broad CD4+ and CD8+ T-cell coverage across the SARS-CoV-2 spike protein.