Longitudinal Immune Profiling and Corticosteroid Modulation of the Immediate Innate Immune Response to ChAdOx1 nCoV-19

ChAdOx1 nCoV-19, a chimpanzee adenovirus (ChAd)-vector vaccine expressing the SARS-CoV-2 spike protein, has elicited robust immunological responses in large populations. Despite its proven efficacy and safety, some recipients have reported immediate inflammatory reactions post-vaccination. We comprehensively examined the immune landscape following ChAdOx1 nCoV-19 vaccination based on the epigenomic profiles of monocytes. Glucocorticoids are wildly used as steroid anti-inflammatory drugs to modify acute and chronic inflammation. Recently, dexamethasone is used to modify inflammation in COVID19 and side-effects after COVID19 vaccination. ChAdox1 nCoV-19 induces interferon responses and inflammation in human. In addition to IFNa, TNF and IL1b treatment to mimic inflammatory environment gives general effects of glucocorticoids in complex inflammatory context. Peripheral blood samples were obtained from five healthy volunteers at four post-ChAdOx1 nCoV-19 vaccination time points: days 0 (baseline), 1, 3, and 14. To mimic COVID19 and inflammatory environment, we pre-treated combination of IFNa(1000U), TNF(20ng), and IL1b(20ug) to 1 million of PBMC derived CD14+ cells with 100mg/ml of MCSF. In order to investigate glucocorticoid effects in chromatin-remodeling level, we treated 100nM of Dexamethasone to each condition at 3h after cytokine treatment. Cells are havested 12h after dexamethasone treatment.