In a population of 42 Philadelphia negative myeloproliferative neoplasm patients, all on systemic active treatment, the likelihood of responding to anti-SARS-CoV-2 BNT162b2 vaccine at 2 weeks after the second dose was significantly lower in the ten patients with myelofibrosis compared to the 32 with essential thrombocythemia (n = 17) and polycythemia vera (n = 15) grouped together, both in terms of neutralizing anti-SARS-CoV-2 IgG titers and seroprotection rates (32.47 AU/mL vs 217.97 AU/mL, p = 0.003 and 60% vs 93.8%, p = 0.021, respectively). Ruxolitinib, which was the ongoing treatment in five patients with myelofibrosis and three with polycythemia vera, may be implicated in reducing vaccine immunogenicity (p = 0.076), though large prospective study is needed to address this issue.

中文翻译：

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与真性红细胞增多症和原发性血小板增多症相比，骨髓纤维化患者对 BNT162b2 疫苗的反应较低

在 42 名费城阴性骨髓增殖性肿瘤患者中，全部接受全身性积极治疗，10 名骨髓纤维化患者在第二次接种后 2 周对抗 SARS-CoV-2 BNT162b2 疫苗产生反应的可能性显着低于32 名患有原发性血小板增多症 (n = 17) 和真性红细胞增多症 (n = 15) 的患者在中和抗 SARS-CoV-2 IgG 滴度和血清保护率方面（32.47 AU/mL vs 217.97 AU/mL，p = 0.003 和 60% 与 93.8%，分别为 p = 0.021）。Ruxolitinib 是 5 名骨髓纤维化患者和 3 名真性红细胞增多症患者的持续治疗药物，可能与降低疫苗免疫原性有关（p = 0.076），尽管需要大型前瞻性研究来解决这个问题。