Emerg Infect Dis. 2021 May;27(5):1446-1453. doi: 10.3201/eid2705.204912. Epub 2021 Apr 12.
The dynamics underlying severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) reinfection remain poorly understood. We identified a small cluster of patients in Brazil who experienced 2 episodes of coronavirus disease (COVID-19) in March and late May 2020. In the first episode, patients manifested an enhanced innate response compared with healthy persons, but neutralizing humoral immunity was not fully achieved. The second episode was associated with different SARS-CoV-2 strains, higher viral loads, and clinical symptoms. Our finding that persons with mild COVID-19 may have controlled SARS-CoV-2 replication without developing detectable humoral immunity suggests that reinfection is more frequent than supposed, but this hypothesis is not well documented.
严重急性呼吸综合征冠状病毒 2（SARS-CoV-2）再感染的基础动力学仍知之甚少。我们在巴西发现了一小群患者，他们在 2020 年 3 月和 5 月底经历了两次冠状病毒病（COVID-19）。在第一次发作中，与健康人相比，患者表现出增强的先天反应，但未完全实现中和体液免疫。第二次发作与不同的 SARS-CoV-2 株、更高的病毒载量和临床症状有关。我们的发现表明，患有轻度 COVID-19 的人可能已经控制了 SARS-CoV-2 的复制，而没有产生可检测到的体液免疫，这表明再感染比预期更为频繁，但这一假设尚未得到充分证实。
