Characterizing the cellular and molecular variabilities of peripheral immune cells in healthy recipients of BBIBP-CorV inactivated SARS-CoV-2 vaccine by single-cell RNA sequencing

The study investigates the immune cell transcription and T cell/B cell receptor dynamics after vaccination with the inactivated SARS-CoV-2 vaccine BBIBP-CorV. The researchers performed single-cell RNA and TCR/BCR sequencing on peripheral blood mononuclear cells at four time points after immunization and found an enrichment of monocytes, central memory CD4+ T cells, type 2 helper T cells, and memory B cells following vaccination. They also identified a clonal expansion of CD4+ T cells following a booster vaccination, which corresponded to a decrease in the TCR diversity of central memory CD4+ T cells and type 2 helper T cells. Finally, the study compared the immune responses elicited by vaccination and SARS-CoV-2 infection to explore the immune responses under different stimuli. The findings provide molecular and cellular evidence for the CD4+ T cell-dependent antibody response induced by the BBIBP-CorV vaccine.