Changing in adaptive cellular repertoire after different SARS-CoV-2 VOCs infection in a cohort of vaccinated Healthcare workers

Despite currently approved vaccines are highly effective in protecting against hospitalization and severe Covid-19 infections, however, their effectiveness in counteracting symptoms presentation and breakthrough infections appears to decrease over time. How pre-existing immunity responds to new variants with mutated antigens is a crucial information to elucidate the functional interplay between antibodies, B and T cell responses during infection with new SARS-CoV-2 variants. In this study, we monitored the dynamics and persistence of the immune response versus different SARS-CoV-2 variants of concern emerged during the pandemic period (2021-2022), in a cohort of vaccinated health care workers, who experienced breakthrough infection in the Pre-Delta, Delta and Omicron waves. Our results suggest a direct dependence between VOCs and different humoral and B and T cells balance in the post-infection period, despite the administration of a different number of vaccine doses and the elapsed time since the last vaccination.尽管目前获批的新冠疫苗在预防重症新冠肺炎住院与重症感染方面效果优异，但在减轻症状发作与阻断突破性感染方面的保护效力却会随时间推移逐渐减弱。预存免疫对携带突变抗原的新型冠状病毒（SARS-CoV-2）新变异株的响应机制，是阐明该病毒变异株感染过程中抗体、B细胞与T细胞应答间功能互作的关键信息。本研究针对2021-2022年新冠大流行期间出现的各类新型冠状病毒关切变异株（VOC），以曾在德尔塔前、德尔塔及奥密克戎疫情浪潮中发生突破性感染的疫苗接种医护人员队列作为研究对象，监测了其针对不同变异株的免疫应答动态与持久性。研究结果显示，即便接种疫苗剂次与末次疫苗接种后的间隔时间存在差异，感染后阶段的体液免疫、B细胞与T细胞平衡状态仍与各类VOC存在直接关联。