Long-lived bone marrow plasma cells (BMPCs) are a persistent and essential source of protective antibodies^{1,2,3,4,5,6,7}. Individuals who have recovered from COVID-19 have a substantially lower risk of reinfection with SARS-CoV-2^8,9,10. Nonetheless, it has been reported that levels of anti-SARS-CoV-2 serum antibodies decrease rapidly in the first few months after infection, raising concerns that long-lived BMPCs may not be generated and humoral immunity against SARS-CoV-2 may be short-lived^11,12,13. Here we show that in convalescent individuals who had experienced mild SARS-CoV-2 infections (n = 77), levels of serum anti-SARS-CoV-2 spike protein (S) antibodies declined rapidly in the first 4 months after infection and then more gradually over the following 7 months, remaining detectable at least 11 months after infection. Anti-S antibody titres correlated with the frequency of S-specific plasma cells in bone marrow aspirates from 18 individuals who had recovered from COVID-19 at 7 to 8 months after infection. S-specific BMPCs were not detected in aspirates from 11 healthy individuals with no history of SARS-CoV-2 infection. We show that S-binding BMPCs are quiescent, which suggests that they are part of a stable compartment. Consistently, circulating resting memory B cells directed against SARS-CoV-2 S were detected in the convalescent individuals. Overall, our results indicate that mild infection with SARS-CoV-2 induces robust antigen-specific, long-lived humoral immune memory in humans.

长寿骨髓浆细胞 (BMPCs) 是保护性抗体^{1,2,3,4,5,6,7}的持久和重要来源。从 COVID-19 中康复的个人再次感染 SARS-CoV-2 ^8,9,10的风险大大降低。尽管如此，据报道，在感染后的最初几个月内，抗 SARS-CoV-2 血清抗体水平迅速下降，这引起了人们对可能不会产生长寿命的 BMPC 并且可能会产生针对 SARS-CoV-2 的体液免疫的担忧。短暂的^11,12,13。在这里，我们展示了在经历过轻度 SARS-CoV-2 感染的恢复期个体中（n = 77)，血清抗 SARS-CoV-2 刺突蛋白 (S) 抗体水平在感染后的前 4 个月迅速下降，然后在接下来的 7 个月内逐渐下降，在感染后至少 11 个月仍可检测到。抗 S 抗体滴度与 18 名在感染后 7 至 8 个月从 COVID-19 康复的人的骨髓抽吸物中 S 特异性浆细胞的频率相关。在 11 名没有 SARS-CoV-2 感染史的健康个体的抽吸物中未检测到 S 特异性 BMPC。我们表明 S 结合 BMPCs 是静止的，这表明它们是稳定隔间的一部分。一致地，在恢复期个体中检测到针对 SARS-CoV-2 S 的循环静息记忆 B 细胞。全面的，