Bionanotechnology Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, Republic of Korea; Bio-Analytical Science Division, University of Science and Technology, Daejeon, Republic of Korea.
Bio-Analytical Science Division, University of Science and Technology, Daejeon, Republic of Korea.
Biochem Biophys Res Commun. 2023 Feb 26;646:8-18. doi: 10.1016/j.bbrc.2023.01.052. Epub 2023 Jan 19.
A severe acute respiratory syndrome coronavirus 2(SARS-CoV-2) surrogate virus neutralization test (sVNT) was used to determine the degree of inhibition of binding between human angiotensin converting enzyme 2 (hACE2) and the receptor binding domain (RBD) of spike protein by neutralizing antibodies in a biosafety level 2 facility. Here, to improve the sensitivity and specificity of the commercial sVNT, we developed a new biotin based sVNT using biotinylated RBD and HRP conjugated streptavidin instead of HRP conjugated RBD for direct detection in an ELISA assay that strongly correlated to the FDA approved cPass sVNT commercial kit (R = 0.8521) and pseudo virus neutralization test (R = 0.9006) (pVNT). The biotin based sVNT was evaluated in 535 postvaccination serum samples corresponding to second and third boosts of AZD1222 and BNT162b2 vaccines of the wild type strain. We confirmed that the neutralizing antibodies against SARS-CoV-2 variants in second vaccination sera decreased after a median of 141.5 days. Furthermore, vaccination sera from BNT162b2-BNT162b2 vaccines maintained neutralizing antibodies for longer than those of AZD1222 only vaccination. In addition, both vaccines maintained high neutralizing antibodies in third vaccination sera against Omicron BA.2 after a median of 27 days, but neutralizing antibodies significantly decreased after a median of 141.5 days. Along with the cPass sVNT commercial kit, biotin based sVNTs may also be suitable for specifically detecting neutralizing antibodies against multiple SARS-CoV-2 variants; however, to initially monitor the neutralizing antibodies in vaccinated sera using high throughput screening, conventional PRNT could be replaced by sVNT to circumvent the inconvenience of a long test time.
采用严重急性呼吸综合征冠状病毒 2（SARS-CoV-2）假病毒中和试验（sVNT），在生物安全 2 级实验室中测定中和抗体对人血管紧张素转化酶 2（hACE2）与刺突蛋白受体结合域（RBD）结合的抑制程度。在此，为提高商业 sVNT 的灵敏度和特异性，我们开发了一种新的基于生物素的 sVNT，使用生物素化 RBD 和 HRP 缀合链霉亲和素代替 HRP 缀合 RBD 进行直接检测，该方法与 FDA 批准的 cPass sVNT 商业试剂盒（R = 0.8521）和假病毒中和试验（R = 0.9006）（pVNT）具有强相关性。该基于生物素的 sVNT 在 535 份对应 AZD1222 和 BNT162b2 疫苗野生型株第二和第三加强针的接种后血清样本中进行了评估。我们证实，第二针接种血清中针对 SARS-CoV-2 变体的中和抗体在中位数 141.5 天后下降。此外，与仅接种 AZD1222 疫苗的血清相比，来自 BNT162b2-BNT162b2 疫苗的接种血清可保持更长时间的中和抗体。此外，两种疫苗在中位数 27 天后的第三针接种血清中对奥密克戎 BA.2 仍保持高中和抗体，但在中位数 141.5 天后，中和抗体显著下降。与 cPass sVNT 商业试剂盒一样，基于生物素的 sVNT 也可能适用于特异性检测针对多种 SARS-CoV-2 变体的中和抗体；然而，为了使用高通量筛选对接种血清中的中和抗体进行初步监测，可以用 sVNT 代替 PRNT，以避免测试时间长带来的不便。
