Background/Objectives: The COVID-19 vaccine is a significant technological advancement with widespread global use. However, its effect on cancer immunity, particularly with repeated vaccinations, remains unclear. We aimed to investigate the relationship between repeated vaccinations and pancreatic cancer (PC) prognosis. Additionally, we examined serum IgG4 levels, known to be an immune suppressor which increases with repeated vaccinations.Methods: We retrospectively examined the effect of vaccination on survival in 272 PC patients diagnosed at our hospital from January 2018 to November 2023 and analyzed prognostic factors, including IgG4 levels in 96 PC patients. Immunohistochemistry for Foxp3 in the tumor tissue was performed, and the serum IgG4 level was measured. Serum samples from 79 patients with benign and malignant diseases, including PC, were collected between September and November 2023, and the spike-specific IgG4 level was determined using an enzyme-linked immunosorbent assay.Results: The overall survival (OS) of PC patients was shortened in those vaccinated three times or more, and the total serum IgG4 levels increased with the number of vaccinations. Of note, OS was significantly shorter in the high IgG4 group, and Foxp3-positive cells in the tumor tissues were increased. Repeated vaccinations increased the spike-specific IgG4 levels, and a positive correlation was observed between spike-specific IgG4 and the total IgG4.Conclusions: These findings highlight repeated vaccination as a poor prognostic factor in PC patients and suggest that IgG4 is induced by repeated vaccination and may be associated with a poor prognosis in these patients.
**背景/目的：** 新型冠状病毒疫苗是一项在全球广泛应用的重要技术进步。然而，其对癌症免疫的影响，特别是在重复接种的情况下，仍不明确。本研究旨在探讨重复接种疫苗与胰腺癌患者预后的关系。此外，我们检测了已知具有免疫抑制作用且随重复接种而增加的血清IgG4水平。 **方法：** 我们回顾性分析了2018年1月至2023年11月期间在我院诊断的272例胰腺癌患者中疫苗接种对生存期的影响，并分析了包括96例胰腺癌患者IgG4水平在内的预后因素。对肿瘤组织进行了Foxp3免疫组化染色，并测量了血清IgG4水平。在2023年9月至11月期间，收集了包括胰腺癌在内的79例良恶性疾病患者的血清样本，并使用酶联免疫吸附法测定了刺突蛋白特异性IgG4水平。 **结果：** 接种三次或以上疫苗的胰腺癌患者总生存期缩短，且血清总IgG4水平随接种次数增加而升高。值得注意的是，高IgG4组患者的总生存期显著缩短，且肿瘤组织中Foxp3阳性细胞增多。重复接种疫苗增加了刺突蛋白特异性IgG4水平，并且观察到刺突蛋白特异性IgG4与总IgG4水平呈正相关。 **结论：** 这些发现表明，重复接种是胰腺癌患者的不良预后因素，并提示IgG4由重复接种诱导，可能与这些患者的不良预后相关。
肿瘤(癌症)患者之家