Abstract
A gradual decay in humoral and cellular immune responses over time upon SAR1S-CoV-2 vaccination may cause a lack of protective immunity. We conducted a longitudinal analysis of antibodies, T cells, and monocytes in 25 participants vaccinated with mRNA or ChAdOx1-S up to 12 weeks after the 3 rd (booster) dose with mRNA vaccine. We observed a substantial increase in antibodies and CD8 T cells specific for the spike protein of SARS-CoV-2 after vaccination. Moreover, vaccination induced activated T cells expressing CD69, CD137 and producing IFN-γ and TNF-α. Virus-specific CD8 T cells showed predominantly memory phenotype. Although the level of antibodies and frequency of virus-specific T cells reduced 4-6 months after the 2 nd dose, they were augmented after the 3 rd dose followed by a decrease later. Importantly, T cells generated after the 3 rd vaccination were also reactive against Omicron variant, indicated by a similar level of IFN-γ production after stimulation with Omicron peptides. Breakthrough infection in participants vaccinated with two doses induced more SARS-CoV-2-specific T cells than the booster vaccination. We found an upregulation of PD-L1 expression on monocytes but no accumulation of myeloid cells with MDSC-like immunosuppressive phenotype after the vaccination. Our results indicate that the 3 rd vaccination fosters antibody and T cell immune response independently from vaccine type used for the first two injections. However, such immune response is attenuated over time, suggesting thereby the need for further vaccinations.
Keywords: SARS-CoV-2; T cell response; antibodies; booster dose; mRNA vaccine; vector vaccine.
【저자키워드】 antibodies, SARS-CoV-2, mRNA vaccine, booster dose, T cell response, vector vaccine., 【초록키워드】 Vaccine, immune response, vaccination, antibody, Cellular immune response, T cells, variant, Infection, omicron, memory, monocyte, PD-L1, T cell, protective immunity, mRNA, peptides, phenotype, expression, booster, IFN-γ, TNF-α, booster vaccination, ChAdOx1-S, longitudinal analysis, Frequency, Vaccinations, dose, CD69, CD8 T cell, immunosuppressive, humoral, Injections, participant, upregulation, myeloid cell, CD137, decrease, reactive, lack, indicated, conducted, reduced, the spike protein, increase in, producing, expressing, virus-specific T cell, activated T cell, SARS-CoV-2-specific T cell, 【제목키워드】 Antibody Response, T cell, dose,