PDF(Pubmed)
Abstract：
Neutralizing antibodies (NtAbs) against severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) are indicators of vaccine efficacy that enable immunity surveillance. However, the rapid mutation of SARS-CoV-2 variants prevents the timely establishment of standards required for effective XBB vaccine evaluation. Therefore, we prepared four candidate standards (No. 11, No. 44, No. 22, and No. 33) using plasma, purified immunoglobulin, and a broad-spectrum neutralizing monoclonal antibody. Collaborative calibration was conducted across nine Chinese laboratories using neutralization methods against 11 strains containing the XBB and BA.2.86 sublineages. This study demonstrated the reduced neutralization potency of the first International Standard antibodies to SARS-CoV-2 variants of concern against XBB variants. No. 44 displayed broad-spectrum neutralizing activity against XBB sublineages, effectively reduced interlaboratory variability for nearly all XBB variants, and effectively minimized the geometric mean titer (GMT) difference between the live and pseudotyped virus. No. 22 showed a broader spectrum and higher neutralizing activity against all strains but failed to reduce interlaboratory variability. Thus, No. 44 was approved as a National Standard for NtAbs against XBB variants, providing a unified NtAb measurement standard for XBB variants for the first time. Moreover, No. 22 was approved as a national reference reagent for NtAbs against SARS-CoV-2, offering a broad-spectrum activity reference for current and potentially emerging variants.
摘要：
针对严重急性呼吸综合征冠状病毒-2(SARS-CoV-2)的中和抗体(NtAbs)是能够实现免疫监视的疫苗效力的指标。然而,SARS-CoV-2变异体的快速突变妨碍了及时建立有效XBB疫苗评估所需的标准.因此,我们准备了四个候选标准(编号11号44号22、不33）使用等离子体，纯化的免疫球蛋白，和广谱中和单克隆抗体。在9个中国实验室中，使用中和方法对11个含有XBB和BA.2.86亚谱系的菌株进行了协同校准。该研究证明了针对关注的SARS-CoV-2变体的第一个国际标准抗体对XBB变体的中和效力降低。不。44显示了对XBB亚谱系的广谱中和活性，有效降低几乎所有XBB变体的实验室间变异性，并有效地最小化活病毒和假型病毒之间的几何平均滴度（GMT）差异。不。图22显示针对所有菌株的更广谱和更高的中和活性,但未能降低实验室间变异性。因此，不。44被批准为NtAbs针对XBB变体的国家标准，首次为XBB变体提供统一的NtAb测量标准。此外，不。22被批准为针对SARS-CoV-2的NtAb的国家参考试剂，为当前和潜在的新兴变体提供广谱活性参考。
