Sullivan Adam, Alfego David, Hu Pingsha, Gillim Laura, Grover Ajay, Garcia Chris, Cohen Oren, Letovsky Stan
LabCorp: Laboratory Corporation of America Holdings, Burlington, NC, United States.
Heliyon. 2023 Feb;9(2):e13103. doi: 10.1016/j.heliyon.2023.e13103. Epub 2023 Jan 21.
Despite a growing amount of data around the kinetics and durability of the antibody response induced by vaccination and previous infection, there is little understanding of whether or not a given quantitative level of antibodies correlates to protection against SARS-CoV-2 infection or reinfection. In this study, we examine SARS-CoV-2 anti-spike receptor binding domain (RBD) antibody titers and subsequent SARS-CoV-2 reverse transcription polymerase chain reaction (RT-PCR) tests in a large cohort of US-based patients. We analyzed antibody test results in a cohort of 22,204 individuals, 6.8% (n = 1,509) of whom eventually tested positive for SARS-CoV-2 RNA, suggesting infection or reinfection. Kaplan-Meier curves were plotted to understand the effect of various levels of anti-spike RBD antibody titers (classified into discrete ranges) on subsequent RT-PCR positivity rates. Statistical analyses included fitting a Cox proportional hazards model to estimate the age-, sex- and exposure-adjusted hazard ratios for S antibody titer, using zip-code positivity rates by week as a proxy for COVID-19 exposure. It was found that the best models of the temporally associated infection risk were those based on log antibody titer level (HR = 0.836 (p < 0.05)). When titers were binned, the hazard ratio associated with antibody titer >250 Binding Antibody Units (BAU) was 0.27 (p < 0.05, 95% CI [0.18, 0.41]), while the hazard ratio associated with previous infection was 0.20 (p < 0.05, 95% CI [0.10, 0.39]). Fisher exact odds ratio (OR) for Ab titers <250 BAU showed OR = 2.84 (p < 0.05; 95% CI: [2.30, 3.53]) for predicting the outcome of a subsequent PCR test. Antibody titer levels correlate with protection against subsequent SARS-CoV-2 infection or reinfection when examining a cohort of real-world patients who had the spike RBD antibody assay performed.
尽管关于疫苗接种和既往感染所诱导的抗体反应的动力学和持久性的数据越来越多，但对于特定定量水平的抗体是否与预防SARS-CoV-2感染或再感染相关，人们了解甚少。在本研究中，我们在美国一大群患者中检测了SARS-CoV-2抗刺突受体结合域（RBD）抗体滴度以及随后的SARS-CoV-2逆转录聚合酶链反应（RT-PCR）检测结果。我们分析了22204名个体的抗体检测结果，其中6.8%（n = 1509）最终SARS-CoV-2 RNA检测呈阳性，提示感染或再感染。绘制Kaplan-Meier曲线以了解不同水平的抗刺突RBD抗体滴度（分为不同范围）对后续RT-PCR阳性率的影响。统计分析包括拟合Cox比例风险模型，以估计S抗体滴度的年龄、性别和暴露调整后的风险比，使用每周邮政编码阳性率作为COVID-19暴露的代理指标。结果发现，与时间相关的感染风险的最佳模型是基于对数抗体滴度水平的模型（HR = 0.836，p < 0.05）。当对滴度进行分组时，抗体滴度>250结合抗体单位（BAU）的风险比为0.27（p < 0.05，95%CI [0.18, 0.41]），而既往感染的风险比为0.20（p < 0.05，95%CI [0.10, 0.39]）。抗体滴度<250 BAU的Fisher精确优势比（OR）显示，预测后续PCR检测结果的OR = 2.84（p < 0.05；95%CI：[2.30, 3.53]）。在对进行了刺突RBD抗体检测的真实世界患者队列进行研究时，抗体滴度水平与预防后续SARS-CoV-2感染或再感染相关。
