Accurate serology for SARS-CoV-2 and common human coronaviruses using a multiplex approach

Serology is a crucial part of the public health response to the ongoing SARS-CoV-2 pandemic. Here, we describe the development, validation and clinical evaluation of a protein micro-array as a quantitative multiplex immunoassay that can identify S and N-directed SARS-CoV-2 IgG antibodies with high specificity and sensitivity and distinguish them from all currently circulating human coronaviruses. The method specificity was 100% for SARS-CoV-2 S1 and 96% for N antigen based on extensive syndromic (n=230 cases) and population panel (n=94) testing that also confirmed the high prevalence of seasonal human coronaviruses. To assess its potential role for both SARS-CoV-2 patient diagnostics and population studies, we evaluated a large heterogeneous COVID-19 cohort (n=330) and found an overall sensitivity of 89% (≥ 21 days post onset symptoms (dps)), ranging from 86% to 96% depending on severity of disease. For a subset of these patients longitudinal samples were provided up to 56 dps. Mild cases showed absent or delayed, and lower SARS-CoV-2 antibody responses. Overall, we present the development and extensive clinical validation of a multiplex coronavirus serological assay for syndromic testing, to answer research questions regarding to antibody responses, to support SARS-CoV-2 diagnostics and to evaluate epidemiological developments efficiently and with high-throughput.血清学检测是当前严重急性呼吸综合征冠状病毒2型（SARS-CoV-2）疫情公共卫生应对工作的关键组成部分。本研究介绍了一种作为定量多重免疫分析法（multiplex immunoassay）的蛋白质微阵列（protein micro-array）的开发、验证与临床评价流程，该检测可高特异性、高灵敏度地识别针对SARS-CoV-2刺突蛋白（S）与核衣壳蛋白（N）的IgG抗体，并可将其与当前所有流行的人冠状病毒区分开来。 基于覆盖230例症状群检测样本与94份人群队列样本的大规模验证测试，该方法针对SARS-CoV-2 S1蛋白的特异性达100%，针对N抗原的特异性达96%；该测试同时证实了季节性人冠状病毒的高感染率。 为评估该方法在SARS-CoV-2患者诊断与人群流行病学研究中的应用潜力，本研究对330例异质性新型冠状病毒肺炎（COVID-19）队列样本进行了检测。结果显示，在症状发作后≥21天（dps）的样本中，总体灵敏度达89%，且灵敏度随疾病严重程度不同在86%至96%之间波动。 针对其中部分患者的纵向随访样本（最长至症状发作后56天）的检测结果显示，轻症患者的SARS-CoV-2抗体应答呈现缺失、延迟或水平较低的特征。 综上，本研究完成了一种可用于症状群检测的多重冠状病毒血清学检测方法的开发与大规模临床验证，该方法可用于解答抗体应答相关的科研问题、辅助SARS-CoV-2诊断，并可高效、高通量地开展流行病学趋势评估。