最初的SARS-CoV-2 mRNA疫苗有效性试验中排除了异基因造血干细胞移植（allo-HSCT）受者。在免疫功能受损人群中，如实体肿瘤或血液恶性肿瘤患者中，报道了疫苗反应不佳的情况，这表明需要进行进一步的研究。关于allo-HSCT受者的抗体反应和疫苗有效性的广泛数据是有限的。在我们的单中心回顾性研究中，我们分析了75名接受两剂mRNA疫苗接种的allo-HSCT受者的抗钉刺蛋白IgG抗体反应。我们收集了有关之前的COVID-19感染、B和T淋巴细胞的恢复情况、供体类型、移植物抗宿主病（GVHD）和接种时的免疫抑制药物的数据。对于原始突变株来说，4160个任意单位（AU）/ mL的临界值已与0.95的病毒中和概率相关联。我们还研究了达到这个保守阈值的allo-HSCT受者的数量。据我们所知，目前盛行的Omicron变异株和病毒中和之间不存在相关性。尽管有29.3％（22/75）的患者因慢性GVHD而接受系统性免疫抑制药物，但96％的患者出现了大于50 AU / mL的阳性抗体反应。然而，只有48％（36/75）的患者超过了中和抗体阈值。先前感染过COVID-19的患者的抗体反应明显更高。尽管鼓舞人心，但反应的变异性强调了对抗体的持续监测以及在此人群中考虑额外剂量的COVID-19疫苗的概念。© 2023 Harborside™.

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) recipients were excluded from the initial SARS-CoV-2 mRNA vaccination efficacy trials. Suboptimal vaccine responses have been reported in immunocompromised cohorts such as patients with solid tumors or hematologic malignancies, suggesting the need for additional research. Widespread data on the antibody responses and vaccine efficacy in allo-HSCT recipients is limited. In our single-center, retrospective study, we analyzed the anti-spike IgG antibody responses in 75 allo-HSCT recipients who received a series of two doses of mRNA vaccination. We collected data on previous COVID-19 infection, B and T lymphocyte recovery, donor types, graft-vs.-host disease (GVHD), and immunosuppressive medications at the time of vaccination. With the original variant, a cutoff of 4,160 arbitrary units (AU)/mL has been correlated with a 0.95 probability of a viral neutralization. We also examined the number of allo-HSCT recipients who achieved this conservative threshold. To our knowledge, no correlate exists for the currently prevalent Omicron variant and viral neutralization. Despite 29.3% (22/75) of patients being on systemic immunosuppressive medications due to chronic GVHD, positive antibody responses > 50 AU/mL were seen in 96% of patients. However, only 48% (36/75) of patients were above the neutralizing antibody threshold. Those with previous COVID-19 infection had significantly higher antibody responses. Although encouraging, the variability of the responses underscores the concept of ongoing antibody monitoring as well as consideration of additional doses of the COVID-19 vaccine in this cohort.© 2023 Harborside™.