Institute for Virology, Medical Faculty, University of Düsseldorf, Germany.
Institute for Virology, Medical Faculty, University of Düsseldorf, Germany.
J Virol Methods. 2022 Sep;307:114569. doi: 10.1016/j.jviromet.2022.114569. Epub 2022 Jun 17.
Determination of neutralizing antibody titers is still considered the gold standard for infection protection. A full virus neutralization test (VNT) with replication-competent, infectious SARS-CoV-2, is labor-intensive and requires Biosafety Level 3 certified laboratories. Therefore, several commercial SARS-CoV-2 surrogate virus neutralization tests (sVNTs) have been developed that aim to detect neutralizing antibodies targeting the receptor binding domain (RBD) of the viral spike glycoprotein (S). Neutralizing antibodies to the RBD block its interaction with the angiotensin-converting enzyme 2 (ACE2) receptor protein. Here, we compared a full virus neutralization test (VNT) with two SARS-CoV-2 surrogate virus neutralization tests (sVNT) and validated them in two cohorts of i) convalescent SARS-CoV-2-infected individuals and ii) COVID vaccinated individuals. The sVNTs showed highly different results both, compared to the VNT-titers and also between the two cohorts. This indicates that currently, sVNT provide a qualitative instead of a quantitative measurement of neutralizing antibodies. The findings in this work show that the cutoff levels for sVNTs might need to be readjusted for convalescent and vaccinated individuals.
中和抗体滴度的测定仍然被认为是感染保护的金标准。使用具有复制能力的、感染性的 SARS-CoV-2 的全病毒中和试验（VNT）是劳动密集型的，并且需要获得生物安全 3 级认证的实验室。因此，已经开发了几种商业 SARS-CoV-2 替代病毒中和试验（sVNT），旨在检测针对病毒刺突糖蛋白（S）的受体结合域（RBD）的中和抗体。中和抗体针对 RBD 阻断其与血管紧张素转化酶 2（ACE2）受体蛋白的相互作用。在这里，我们比较了全病毒中和试验（VNT）和两种 SARS-CoV-2 替代病毒中和试验（sVNT），并在 i）恢复期 SARS-CoV-2 感染个体和 ii）接种 COVID 疫苗的个体的两个队列中对它们进行了验证。sVNT 与 VNT 滴度相比，以及在两个队列之间，均显示出高度不同的结果。这表明目前，sVNT 提供的是中和抗体的定性而不是定量测量。这项工作的结果表明，sVNT 的截断值可能需要针对恢复期和接种疫苗的个体进行重新调整。
