METHODS: Here, we conducted a longitudinal study on hospitalised moderate and severe COVID-19 patients from the acute phase of disease into convalescence at 5 and 9 months post-symptom onset. Utilising flow cytometry, serological assays as well as B cell and T cell FluoroSpot assays, we assessed the magnitude and specificity of humoral and cellular immune responses during and after human SARS-CoV-2 infection.
RESULTS: During acute COVID-19, we observed an increase in germinal centre activity, a substantial expansion of antibody-secreting cells and the generation of SARS-CoV-2-neutralising antibodies. Despite gradually decreasing antibody levels, we show persistent, neutralising antibody titres as well as robust specific memory B cell responses and polyfunctional T cell responses at 5 and 9 months after symptom onset in both moderate and severe COVID-19 patients.
CONCLUSIONS: Our findings describe the initiation and, importantly, persistence of cellular and humoral SARS-CoV-2-specific immunological memory in hospitalised COVID-19 patients long after recovery, likely contributing towards protection against reinfection.
方法:这里,我们对住院的中重度COVID-19患者进行了一项纵向研究,这些患者从疾病急性期到症状发作后5个月和9个月的恢复期.利用流式细胞术,血清学测定以及B细胞和T细胞荧光斑点测定,我们评估了人类SARS-CoV-2感染期间和之后体液和细胞免疫反应的大小和特异性。
结果:在急性COVID-19期间,我们观察到生发中心活性增加,抗体分泌细胞的大量扩增和SARS-CoV-2中和抗体的产生。尽管抗体水平逐渐下降,我们表现出坚持不懈,在中度和重度COVID-19患者症状发作后5个月和9个月,中和抗体滴度以及稳健的特异性记忆B细胞反应和多功能T细胞反应。
结论:我们的发现描述了启动和,重要的是,住院的COVID-19患者在康复后很长时间内持续存在细胞和体液SARS-CoV-2特异性免疫记忆,可能有助于防止再感染。