Department of Laboratory Medicine, Affiliated Hospital of Jiangnan University, Wuxi, China.
The University of Queensland Diamantina Institute, Brisbane, Queensland, Australia.
JCI Insight. 2023 Aug 8;8(15):e168437. doi: 10.1172/jci.insight.168437.
The inactivated vaccine CoronaVac is one of the most widely used COVID-19 vaccines globally. However, the longitudinal evolution of the immune response induced by CoronaVac remains elusive compared with other vaccine platforms. Here, we recruited 88 healthy individuals who received 3 doses of CoronaVac vaccine. We longitudinally evaluated their polyclonal and antigen-specific CD4+ T cells and neutralizing antibody response after receiving each dose of vaccine for over 300 days. Both the second and third doses of vaccine induced robust spike-specific neutralizing antibodies, with a third vaccine further increasing the overall magnitude of antibody response and neutralization against Omicron sublineages B.1.1.529, BA.2, BA.4/BA.5, and BA.2.75.2. Spike-specific CD4+ T cells and circulating T follicular helper (cTfh) cells were markedly increased by the second and third dose of CoronaVac vaccine, accompanied by altered composition of functional cTfh cell subsets with distinct effector and memory potential. Additionally, cTfh cells were positively correlated with neutralizing antibody titers. Our results suggest that CoronaVac vaccine-induced spike-specific T cells are capable of supporting humoral immunity for long-term immune protection.
科兴新冠病毒灭活疫苗是全球应用最广泛的 COVID-19 疫苗之一。然而，与其他疫苗平台相比，科兴疫苗诱导的免疫反应的纵向演变仍不清楚。在这里，我们招募了 88 名健康个体，他们接受了 3 剂科兴疫苗。我们在 300 多天的时间里，对他们在接受每剂疫苗后的多克隆和抗原特异性 CD4+T 细胞和中和抗体反应进行了纵向评估。第二和第三剂疫苗均诱导了强烈的刺突特异性中和抗体，第三剂疫苗进一步增加了针对奥密克戎亚谱系 B.1.1.529、BA.2、BA.4/BA.5 和 BA.2.75.2 的抗体反应和中和的总体幅度。第二和第三剂科兴疫苗显著增加了刺突特异性 CD4+T 细胞和循环滤泡辅助性 T 细胞（cTfh），同时伴有功能 cTfh 细胞亚群组成的改变，具有不同的效应和记忆潜能。此外，cTfh 细胞与中和抗体滴度呈正相关。我们的研究结果表明，科兴疫苗诱导的刺突特异性 T 细胞能够支持体液免疫，从而提供长期的免疫保护。
