Broad Institute of MIT and Harvard, Cambridge, Massachusetts, USA.
Department of Molecular Biology and Center for Computational and Integrative Biology, Massachusetts General Hospital, Boston, Massachusetts, USA.
mBio. 2023 Apr 25;14(2):e0352322. doi: 10.1128/mbio.03523-22. Epub 2023 Feb 14.
The ability to measure neutralizing antibodies on large scale can be important for understanding features of the natural history and epidemiology of infection, as well as an aid in determining the efficacy of interventions, particularly in outbreaks such as the current severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic. Because of the assay's rapid scalability and high efficiency, serology measurements that quantify the presence rather than function of serum antibodies often serve as proxies of immune protection. Here, we report the development of a high-throughput, automated fluorescence-based neutralization assay using SARS-CoV-2 virus to quantify neutralizing antibody activity in patient specimens. We performed large-scale testing of over 19,000 COVID-19 convalescent plasma (CCP) samples from patients who had been infected with SARS-CoV-2 between March and August 2020 across the United States. The neutralization capacity of the samples was moderately correlated with serological measurements of anti-receptor-binding domain (RBD) IgG levels. The neutralizing antibody levels within these convalescent-phase serum samples were highly variable against the original USA-WA1/2020 strain with almost 10% of individuals who had had PCR-confirmed SARS-CoV-2 infection having no detectable antibodies either by serology or neutralization, and ~1/3 having no or low neutralizing activity. Discordance between neutralization and serology measurements was mainly due to the presence of non-IgG RBD isotypes. Meanwhile, natural infection with the earliest SARS-CoV-2 strain USA-WA1/2020 resulted in weaker neutralization of subsequent B.1.1.7 (alpha) and the B.1.351 (beta) variants, with 88% of samples having no activity against the BA.1 (omicron) variant. The ability to directly measure neutralizing antibodies on live SARS-CoV-2 virus in individuals can play an important role in understanding the efficacy of therapeutic interventions or vaccines. In contrast to functional neutralization assays, serological assays only quantify the presence of antibodies as a proxy of immune protection. Here, we have developed a high-throughput, automated neutralization assay for SARS-CoV-2 and measured the neutralizing activity of ~19,000 COVID-19 convalescent plasma (CCP) samples collected across the United States between March and August of 2020. These data were used to support the FDA's interpretation of CCP efficacy in patients with SARS-CoV-2 infection and their issuance of emergency use authorization of CCP in 2020.
大规模测量中和抗体的能力对于了解感染的自然史和流行病学特征以及确定干预措施的效果很重要，特别是在当前的严重急性呼吸系统综合征冠状病毒 2 (SARS-CoV-2) 大流行等疫情中。由于该检测方法具有快速可扩展性和高效率，因此通常将定量检测血清抗体存在而非功能的血清学测量作为免疫保护的替代指标。在这里，我们报告了一种使用 SARS-CoV-2 病毒的高通量、自动化荧光中和测定法的开发，以定量患者标本中的中和抗体活性。我们对 2020 年 3 月至 8 月期间在美国感染 SARS-CoV-2 的患者的 19,000 多个 COVID-19 恢复期血浆 (CCP) 样本进行了大规模测试。这些样本的中和能力与针对受体结合域 (RBD) IgG 水平的血清学测量呈中度相关。这些恢复期血清样本中的中和抗体水平对原始 USA-WA1/2020 株的变异非常多样化，近 10%的经 PCR 确诊 SARS-CoV-2 感染的个体通过血清学或中和检测均无法检测到抗体，约 1/3 的个体没有或仅有低水平的中和活性。中和和血清学测量之间的差异主要归因于非 IgG RBD 同型的存在。与此同时，最初的 SARS-CoV-2 株 USA-WA1/2020 的自然感染导致对随后的 B.1.1.7 (alpha) 和 B.1.351 (beta) 变体的中和作用减弱，88%的样本对 BA.1(奥密克戎)变体没有活性。直接在活 SARS-CoV-2 病毒上测量个体的中和抗体的能力在理解治疗干预或疫苗的效果方面起着重要作用。与功能中和测定法不同，血清学测定法仅定量抗体的存在作为免疫保护的替代指标。在这里，我们开发了一种用于 SARS-CoV-2 的高通量、自动化中和测定法，并测量了 2020 年 3 月至 8 月期间在美国收集的约 19,000 个 COVID-19 恢复期血浆 (CCP) 样本的中和活性。这些数据用于支持 FDA 对 CCP 在 SARS-CoV-2 感染患者中的疗效的解释，并在 2020 年发布了 CCP 的紧急使用授权。
