Department of Allergy and Clinical Immunology, State Key Laboratory of Respiratory Disease, Guangzhou Institute of Respiratory Health, National Clinical Research Center of Respiratory Disease, First Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.
Clinical Laboratory, Dongguan Eighth People's Hospital, Dongguan, China.
Front Immunol. 2022 Jun 22;13:913732. doi: 10.3389/fimmu.2022.913732. eCollection 2022.
Levels of neutralizing antibodies (NAb) after vaccine against coronavirus disease 2019 (COVID-19) can be detected using a variety of methods. A critical challenge is how to apply simple and accurate methods to assess vaccine effect. In a population inoculated with three doses of the inactivated Sinopharm/BBIBP vaccine, we assessed the performance of chemiluminescent immunoassay (CLIA) in its implementation to detect severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) specific antibodies, as well as the antibody kinetics of healthcare workers throughout the course of vaccination. The antibody levels of NAb, the receptor-binding-domain (RBD) antibodies and IgG peaked one month after the second and remained at a relatively high level for over three months after the booster injection, while IgM and IgA levels remained consistently low throughout the course of vaccination. The production of high-level neutralizing antibodies is more likely when the inoculation interval between the first two doses is within the range of one to two months, and that between the first and booster dose is within 230 days. CLIA showed excellent consistency and correlation between NAb, RBD, and IgG antibodies with the cytopathic effect (CPE) conventional virus neutralization test (VNT). Receiver operating characteristic (ROC) analysis revealed that the optimal cut-off levels of NAb, RBD and IgG were 61.77 AU/ml, 37.86 AU/ml and 4.64 AU/ml, with sensitivity of 0.833, 0.796 and 0.944, and specificity of 0.768, 0.750 and 0.625, respectively, which can be utilized as reliable indicators of COVID-19 vaccination immunity detection.
新型冠状病毒肺炎（COVID-19）疫苗接种后中和抗体（NAb）水平可采用多种方法检测。如何应用简单、准确的方法评估疫苗效果是一个关键挑战。在接种三剂灭活型国药/BBIBP 疫苗的人群中，我们评估了化学发光免疫分析（CLIA）在实施过程中检测严重急性呼吸综合征冠状病毒-2（SARS-CoV-2）特异性抗体的性能，以及医护人员在整个接种过程中的抗体动力学。NAb、受体结合域（RBD）抗体和 IgG 的抗体水平在第二剂后一个月达到峰值，并在加强针注射后三个月以上仍保持较高水平，而 IgM 和 IgA 水平在整个接种过程中一直保持较低水平。当两剂之间的接种间隔在 1 至 2 个月范围内，且第一剂和加强针之间的间隔在 230 天内时，更有可能产生高水平的中和抗体。CLIA 显示 NAb、RBD 和 IgG 抗体与细胞病变效应（CPE）传统病毒中和试验（VNT）之间具有极好的一致性和相关性。受试者工作特征（ROC）分析显示，NAb、RBD 和 IgG 的最佳截断值分别为 61.77 AU/ml、37.86 AU/ml 和 4.64 AU/ml，灵敏度分别为 0.833、0.796 和 0.944，特异性分别为 0.768、0.750 和 0.625，可作为 COVID-19 疫苗接种免疫检测的可靠指标。
