Alandijany Thamir A, El-Kafrawy Sherif A, Tolah Ahmed M, Sohrab Sayed S, Faizo Arwa A, Hassan Ahmed M, Alsubhi Tagreed L, Othman Norah A, Azhar Esam I
Special Infectious Agents Unit, King Fahd Medical Research Center, King Abdulaziz University, P.O. Box 128442, Jeddah 21362, Saudi Arabia.
Department of Medical Laboratory Technology, Faculty of Applied Medical Sciences, King Abdulaziz University, P.O. Box 80324, Jeddah 21589, Saudi Arabia.
Pathogens. 2020 Sep 28;9(10):803. doi: 10.3390/pathogens9100803.
The ongoing coronavirus disease 19 (COVID-19) pandemic, caused by the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), poses a threat to human health. Despite this, many affected countries are now in the process of gradual lifting of COVID-19 restrictions that were initially implemented in response to the pandemic. The success of the so-called "exit strategy" requires continued surveillance of virus circulation in the community and evaluation of the prevalence of protective immunity among population. Serology tests are valuable tools for these purposes. Herein, SARS-CoV-2 full-length spike (S) recombinant protein was utilized to develop and optimize an indirect enzyme-linked immunoassay (ELISA) that enables a reliable detection of virus-specific IgG antibody in human sera. Importantly, the performance of this assay was evaluated utilizing micro-neutralization (MN) assay as a reference test. Our developed ELISA offers 100% sensitivity, 98.4% specificity, 98.8% agreement, and high overall accuracy. Moreover, the optical density (OD) values of positive samples significantly correlated with their MN titers. The assay specifically detects human IgG antibodies directed against SARS-CoV-2, but not those to Middle East respiratory syndrome coronavirus (MERS-CoV) or human coronavirus HKU1 (HCoV-HKU1). The availability of this in-house ELISA protocol would be valuable for various diagnostic and epidemiological applications.
由新型严重急性呼吸综合征冠状病毒2（SARS-CoV-2）引起的新型冠状病毒肺炎（COVID-19）大流行对人类健康构成威胁。尽管如此，许多受影响的国家目前正在逐步解除最初为应对疫情而实施的COVID-19限制措施。所谓“退出策略”的成功需要持续监测社区内病毒的传播情况，并评估人群中保护性免疫的流行程度。血清学检测是实现这些目标的宝贵工具。在此，利用SARS-CoV-2全长刺突（S）重组蛋白开发并优化了一种间接酶联免疫吸附测定（ELISA），该方法能够可靠地检测人血清中病毒特异性IgG抗体。重要的是，该检测方法的性能以微量中和（MN）试验作为参考检测进行了评估。我们开发的ELISA具有100%的灵敏度、98.4%的特异性、98.8%的一致性和较高的总体准确性。此外，阳性样本的光密度（OD）值与其MN滴度显著相关。该检测方法特异性检测针对SARS-CoV-2的人IgG抗体，但不检测针对中东呼吸综合征冠状病毒（MERS-CoV）或人冠状病毒HKU1（HCoV-HKU1）的抗体。这种内部ELISA方案的可用性对于各种诊断和流行病学应用具有重要价值。
