Memory elicitation, T-cell response and antibody production: an independent study of an inactivated entire virus vaccine (Coronavac)

Abstract

Health professionals working to mitigate the COVID-19 pandemic are one of the main risk groups for the disease, being prioritized for vaccination. Considering this, the aim of this study was to analyze the immune response of these professionals immunized with CoronaVac in the fi rst and second doses. Blood samples were collected after the fi rst and second doses of the vaccine (CoronaVac) and used to investigate hematological and biochemical parameters, analysis of immunoglobulin production, cytokines, and gene expression profi le, as well as the identifi cation of subsets of immune cells. Post-fi rst dose immunological phenotypic memory (CD27+) profi les (T CD4+, TCD8+ and CD19+) showed a signifi cant increase, as did Monocyte APCs (CD80+HLA-DR+) in relation to the second dose. The cytokines IL-2, IL-6 and IFN-° showed increased values in relation to the other analyzed cytokines. The Th2/Th17 profi le in the second dose was characterized by gene expression analysis. The production of IgM and IgG after vaccination showed statistically signifi cant values in the comparison between doses. CoronaVac showed activation of APCs monocytes, memory response of T and B lymphocytes, with immunoglobulins production. This set of responses is characterized by the Th2/Th17 immunological profi le.