Abstract：
The effect of COVID-19 booster vaccination on SARS-CoV-2 T-cell mediated immune responses in elderly nursing home residents has not been explored in depth. Thirty-nine elderly nursing home residents (median age, 91 years) were included, all fully vaccinated with mRNA vaccines. The frequency of and the integrated mean fluorescence (iMFI) for peripheral blood SARS-CoV-2-Spike reactive IFN-γ-producing CD4+ or CD8+ T cells before and after the first (Pre-3D and Post-3D) and second (Pre-4D and Post-4D) vaccine booster doses was determined using flow cytometry for an intracellular staining method. 3D increased significantly (p = 0.01) the percentage of participants displaying detectable SARS-CoV-2-T-cell responses compared with pre-3D (97% vs. 74%). The magnitude of the increase was statistically significant for CD8+ T cells (p = 0.007) but not for CD4+ T cells (p = 0.77). A trend towards higher frequencies of peripheral blood SARS-CoV-2-CD8+ T cells was observed post-3D compared with pre-3D (p = 0.06). The percentage of participants with detectable SARS-S-CoV-2 CD4+ T-cell responses decreased post-4D (p = 0.035). Following 4D, a nonsignificant decrease in the frequencies of both T cell subsets was noticed (p = 0.94 for CD8+ T cells and p = 0.06 for CD4+ T cells). iMFI data mirrored that of T-cell frequencies. The kinetics of SARS-CoV-2 CD8+ and CD4+ T cells following receipt of 3D and 4D were comparable across SARS-CoV-2-experienced and -naïve participants and between individuals receiving a homologous or heterologous vaccine booster. 3D increased the percentage of elderly nursing home residents displaying detectable SARS-CoV-2 T-cell responses but had a marginal effect on T-cell frequencies. The impact of 4D on SARS-CoV-2 T-cell responses was negligible; whether this was due to suboptimal priming or rapid waning could not be ascertained.
摘要：
COVID-19加强疫苗接种对老年养老院居民SARS-CoV-2T细胞介导的免疫反应的影响尚未深入探讨。39名老年疗养院居民(平均年龄，91年)被包括在内，全部接种mRNA疫苗。在第一次(前3D和后3D)和第二次(前4D和后4D)疫苗加强剂量之前和之后,外周血SARS-CoV-2-穗反应性IFN-γ-产生CD4+或CD8+T细胞的频率和积分平均荧光(iMFI)使用流式细胞术进行细胞内染色方法测定。与3D之前相比，3D显着增加（p=0.01）显示可检测的SARS-CoV-2-T细胞反应的参与者百分比（97％vs.74%)。对于CD8+T细胞(p=0.007),但对于CD4+T细胞(p=0.77),增加的幅度在统计学上是显著的。与3D前相比，3D后观察到外周血SARS-CoV-2-CD8T细胞出现更高频率的趋势（p=0.06）。4D后可检测到SARS-S-CoV-2CD4T细胞反应的参与者百分比降低（p=0.035）。在4D之后，观察到两种T细胞亚群的频率均无显著下降(CD8+T细胞p=0.94,CD4+T细胞p=0.06).iMFI数据反映了T细胞频率的数据。在接受3D和4D后，SARS-CoV-2CD8和CD4T细胞的动力学在有SARS-CoV-2经验和未接触过的参与者之间以及接受同源或异源疫苗加强剂的个体之间具有可比性。3D增加了显示可检测的SARS-CoV-2T细胞反应的老年疗养院居民的百分比，但对T细胞频率有边际影响。4D对SARS-CoV-2T细胞反应的影响可以忽略不计；无法确定这是由于未达到理想的启动还是快速减弱。
