COVID-19 is an ongoing pandemic with high morbidity and mortality. Despite meticulous research, only dexamethasone has shown consistent mortality reduction. Convalescent plasma (CP) infusion might also develop into a safe and effective treatment modality on the basis of recent studies and meta-analyses; however, little is known regarding the kinetics of antibodies in CP recipients. To evaluate the kinetics, we followed 31 CP recipients longitudinally enrolled at a median of 3 days post symptom onset for changes in binding and neutralizing antibody titers and viral loads. Antibodies against the complete trimeric Spike protein and the receptor-binding domain (Spike-RBD), as well as against the complete Nucleocapsid protein and the RNA binding domain (N-RBD) were determined at baseline and weekly following CP infusion. Neutralizing antibody (pseudotype NAb) titers were determined at the same time points. Viral loads were determined semi-quantitatively by SARS-CoV-2 PCR. Patients with low humoral responses at entry showed a robust increase of antibodies to all SARS-CoV-2 proteins and Nab, reaching peak levels within 2 weeks. The rapid increase in binding and neutralizing antibodies was paralleled by a concomitant clearance of the virus within the same timeframe. Patients with high humoral responses at entry demonstrated low or no further increases; however, virus clearance followed the same trajectory as in patients with low antibody response at baseline. Together, the sequential immunological and virological analysis of this well-defined cohort of patients early in infection shows the presence of high levels of binding and neutralizing antibodies and potent clearance of the virus.

中文翻译：

---

接受恢复期血浆治疗的重症 COVID-19 患者的核衣壳、尖峰抗体和中和抗体以及病毒载量的动力学

COVID-19 是一种具有高发病率和死亡率的持续流行病。尽管进行了细致的研究，但只有地塞米松显示出持续的死亡率降低。根据最近的研究和荟萃分析，恢复期血浆 (CP) 输注也可能发展成为一种安全有效的治疗方式；然而，关于 CP 受体中抗体的动力学知之甚少。为了评估动力学，我们跟踪了 31 名 CP 接受者，他们在症状出现后平均 3 天纵向登记了结合和中和抗体滴度和病毒载量的变化。在基线和 CP 输注后每周测定针对完整三聚体 Spike 蛋白和受体结合域 (Spike-RBD) 以及针对完整核衣壳蛋白和 RNA 结合域 (N-RBD) 的抗体。在相同的时间点测定中和抗体（伪型 NAb）滴度。通过 SARS-CoV-2 PCR 半定量测定病毒载量。入院时体液反应低的患者表现出针对所有 SARS-CoV-2 蛋白和 Nab 的抗体强劲增加，并在 2 周内达到峰值水平。结合和中和抗体的快速增加与病毒在同一时间范围内的清除同时发生。进入时体液反应高的患者表现出低或没有进一步增加；然而，病毒清除遵循与基线时抗体反应低的患者相同的轨迹。一起，