新冠病毒感染康复患者及疫苗接种者特异性T细胞应答远期特征研究及精准评估体系的建立

新型冠状病毒（SARS-CoV-2）特异性记忆T细胞应答是COVID-19群体免疫力的重要组成部分，揭示其远期变化特征和规律对防疫政策决策具有重要意义。目前尚不清楚SARS-CoV-2感染康复者及疫苗接种者体内形成的病毒特异性记忆T细胞应答远期如何变化，以及哪些免疫和临床指标可以高效预测和评估T细胞应答水平的远期变化。本团队前期在已建立的SARS-CoV-2感染康复患队列中研究了起病1年后体内记忆性T细胞应答的动态变化特征及其基线期免疫细胞变化。本项目拟在前期研究基础上，增加入组患者数量并纳入疫苗接种者，在更长时间维度上全景动态描绘康复患者及疫苗接种者病毒特异性记忆T细胞应答及其相关免疫细胞亚群的基线和远期变化特征；通过生物信息学分析和机器学习算法，建立精准预测和评估记忆T细胞应答水平变化的指标体系。本项目的开展将为新冠肺炎免疫防控策略制订提供数据和理论基础支持。

SARS-CoV-2 specific memory T cell response is an important component of COVID-19 herd immunity, and revealing its changing characteristics and patterns in a long-term is of great significance for making epidemic prevention policies. It remains unclear how SARS-CoV-2 specific memory T cell response changes in convalescent and vaccinated individuals in the long-term, and which immune and clinical markers can effectively predict and evaluate the long-term changes of the SARS-CoV-2 specific memory T cell response. Our team has previously characterized the kinetics of SARS-CoV-2 specific T cell response and the changes of immune cells at baseline in convalescent COVID-19 individuals up to one year post disease onset in our patient cohort. In the current project, we will increase the number of enrolled convalescent individuals and include vaccine recipients, to dynamically depict the baseline and long-term characteristics of SARS-CoV-2 specific memory T cell responses and related immune cell subsets in a longer time period. We will establish index systems for predicting and evaluating the SARS-CoV-2 memory T cell response through bioinformatics analysis and machine learning algorithm. The findings of project will provide experimental and theoretical supports for designing COVID-19 prevention and control strategies.