Abstract:
Antibody responses to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are multi-targeted and variable over time. Multiplex quantitative serological assays are needed to provide accurate and robust seropositivity data for the establishment of serological signatures during vaccination and or infection. We describe here the validation and evaluation of an electro-chemiluminescence (ECL)-based Mesoscale Discovery assay (MSD) for estimation of total and functional IgG relative to SARS-CoV-2 spike, nucleocapsid and receptor binding (RBD) proteins in human serum samples to establish serological signatures of SARS-CoV-2 natural infection and breakthrough cases. The 9-PLEX assay was validated as per ICH, EMA, and US FDA guidelines using a panel of sera samples, including the NIBSC/WHO reference panel (20/268). The assay demonstrated high specificity and selectivity in inhibition assays, wherein the homologous inhibition was more than 85% and heterologous inhibition was below 10%. The assay also met predetermined acceptance criteria for precision (CV < 20%), accuracy (70-130%) and dilutional linearity. The method\'s applicability to serological signatures was demonstrated using sera samples (n = 45) representing vaccinated, infected and breakthrough cases. The method was able to establish distinct serological signatures and thus provide a potential tool for seroprevalence of SARS-CoV-2 during vaccination or infection.
摘要:
严重急性呼吸综合征冠状病毒2(SARS-CoV-2)的抗体反应是多目标的,并且随时间变化。需要多重定量血清学测定以提供准确且稳健的血清阳性数据,用于在疫苗接种和/或感染期间建立血清学特征。我们在这里描述了基于电化学发光(ECL)的中尺度发现测定(MSD)的验证和评估,用于估计相对于SARS-CoV-2峰值的总和功能性IgG,人血清样品中的核衣壳和受体结合(RBD)蛋白,以建立SARS-CoV-2自然感染和突破性病例的血清学特征。9-PLEX测定按照ICH进行验证,EMA,和美国FDA指南使用一组血清样本,包括NIBSC/世卫组织参考小组(20/268)。该测定法在抑制测定法中显示出高特异性和选择性,其中同源抑制超过85%并且异源抑制低于10%。该测定还符合预定的精度接受标准(CV<20%),准确度(70-130%)和稀释线性。使用代表接种疫苗的血清样本(n=45)证明了该方法对血清学特征的适用性,感染和突破性病例。该方法能够建立不同的血清学特征,因此为疫苗接种或感染期间SARS-CoV-2的血清阳性率提供了潜在的工具。