Yanamandra Uday, Tandel Kundan, Rayapureddi Karthik, Singh Sanjay Pratap, Arivalagan Balakrishnan, Kalra Dinesh Kumar, Sahu Rajesh, Menon Anil Shankar, Kotwal Narendra
Professor & Hematologist, Department of Internal Medicine, Armed Forces Medical College, Pune, India.
Associate Professor, Department of Microbiology, Armed Forces Medical College, Pune, India.
Med J Armed Forces India. 2025 May-Jun;81(3):320-327. doi: 10.1016/j.mjafi.2024.05.014. Epub 2024 Jul 4.
In the context of SARS-CoV-2, infection and immunization lead to varied levels of neutralizing antibodies (NAbs) crucial for protective immunity. In the lack of universal availability of plaque reduction neutralization tests, the gold standard centers rely on surrogate kits, for which performance standards and validation are lacking. Hence, we assessed three NAb kits available in India to determine their agreement and concordance.
It's a single-center cross-sectional observation study conducted during the third wave of the pandemic starting in January 2022 amongst individuals (n: 247) who received the first two doses of Covishield. Samples were analysed using kit-A (Indian Council of Medical Research (ICMR) approved NAb microlisa kit, J. Mitra & Co. Pvt. Ltd), kit-B (Food and Drug Administration-approved NAb surrogate virus neutralisation test, GenscriptTM), and kit-C (NARI- and ICMR-approved anti-SARS-CoV-2 IgG antibodies kit using indirect ELISA principle, ErbaLisa® COVID-19 IgG). Cohen's kappa and concordance were analyzed using JMPver20.0.0.
NAb was detected in 80.4%, 82.9%, and 21% samples using the three different kits. Discordance was observed in 19.68%, 65.7%, and 62.6% between Kit A-B, A-C, and B-C, respectively. The agreement was fair between Kit A-B (κ-0.35; p: 0.06) and Kit B-C (κ-0.09; p: 0.0005). Kit-B showed higher mean percentage inhibition (74.6 ± 32.1%) than Kit-A (68.1 ± 35.7%) (p: 0.0347). The correlation between kit-A and kit-B was moderate (r: 0.57; p < 0.0001).
There is significant discordance between various commercials, which raises questions about their validity. The research underscores the need for robust validation and standardization of NAb tests to ensure their reliability and effectiveness in guiding public health strategies.
在新冠病毒（SARS-CoV-2）的背景下，感染和免疫会产生不同水平的中和抗体（NAb），这些抗体对保护性免疫至关重要。由于空斑减少中和试验并非普遍可用，金标准中心依赖替代试剂盒，但这些试剂盒缺乏性能标准和验证。因此，我们评估了印度现有的三种NAb试剂盒，以确定它们之间的一致性和协调性。
这是一项单中心横断面观察性研究，于2022年1月大流行第三波期间，在接受了两剂Covishield疫苗的个体（n = 247）中进行。使用试剂盒A（印度医学研究理事会（ICMR）批准的NAb微酶联免疫吸附测定试剂盒，J. Mitra & Co. Pvt. Ltd）、试剂盒B（美国食品药品监督管理局批准的NAb替代病毒中和试验，GenscriptTM）和试剂盒C（NARI和ICMR批准的采用间接酶联免疫吸附测定原理的抗SARS-CoV-2 IgG抗体试剂盒，ErbaLisa® COVID-19 IgG）对样本进行分析。使用JMPver20.0.0分析Cohen's kappa系数和一致性。
使用三种不同试剂盒分别在80.4%、82.9%和21%的样本中检测到NAb。试剂盒A与B、A与C、B与C之间的不一致率分别为19.68%、65.7%和62.6%。试剂盒A与B之间的一致性一般（κ = 0.35；p = 0.06），试剂盒B与C之间的一致性较差（κ = 0.09；p = 0.0005）。试剂盒B的平均抑制百分比（74.6 ± 32.1%）高于试剂盒A（68.1 ± 35.7%）（p = 0.0347）。试剂盒A与试剂盒B之间的相关性中等（r = 0.57；p < 0.0001）。
各种商业化试剂盒之间存在显著不一致，这引发了对其有效性的质疑。该研究强调了对NAb检测进行有力验证和标准化的必要性，以确保其在指导公共卫生策略方面的可靠性和有效性。
