Department of Microbiology and Immunology, University of Melbourne, at The Peter Doherty Institute for Infection and Immunity, Melbourne, VIC, Australia.
Australian Research Council Centre for Excellence in Convergent Bio-Nano Science and Technology, University of Melbourne, Melbourne, VIC, Australia.
Nat Commun. 2021 Feb 19;12(1):1162. doi: 10.1038/s41467-021-21444-5.
The durability of infection-induced SARS-CoV-2 immunity has major implications for reinfection and vaccine development. Here, we show a comprehensive profile of antibody, B cell and T cell dynamics over time in a cohort of patients who have recovered from mild-moderate COVID-19. Binding and neutralising antibody responses, together with individual serum clonotypes, decay over the first 4 months post-infection. A similar decline in Spike-specific CD4 and circulating T follicular helper frequencies occurs. By contrast, S-specific IgG memory B cells consistently accumulate over time, eventually comprising a substantial fraction of circulating the memory B cell pool. Modelling of the concomitant immune kinetics predicts maintenance of serological neutralising activity above a titre of 1:40 in 50% of convalescent participants to 74 days, although there is probably additive protection from B cell and T cell immunity. This study indicates that SARS-CoV-2 immunity after infection might be transiently protective at a population level. Therefore, SARS-CoV-2 vaccines might require greater immunogenicity and durability than natural infection to drive long-term protection.
感染诱导的 SARS-CoV-2 免疫持久性对再感染和疫苗开发具有重大影响。在这里，我们展示了一组从轻度至中度 COVID-19 中康复的患者的抗体、B 细胞和 T 细胞随时间推移的综合动态。结合抗体和中和抗体反应以及个体血清克隆型在感染后 4 个月内衰减。Spike 特异性 CD4 和循环滤泡辅助 T 细胞频率也出现类似的下降。相比之下，S 特异性 IgG 记忆 B 细胞随着时间的推移持续积累，最终构成循环记忆 B 细胞库的相当大一部分。同时进行的免疫动力学建模预测，在 74 天内，50%的恢复期参与者的血清中和活性将保持在 1:40 的滴度以上，但 B 细胞和 T 细胞免疫可能会提供额外的保护。本研究表明，感染后 SARS-CoV-2 免疫在人群水平上可能是短暂的保护。因此，SARS-CoV-2 疫苗可能需要比自然感染更高的免疫原性和持久性，以实现长期保护。
