了解多发病与抗体持久性之间的关系对于制定疫苗政策至关重要。我们的目标是评估多发病与SARS-CoV-2第一次疫苗接种后9个月的血清学应答之间的关联。我们分析了来自意大利的三个队列以及分别来自德国、罗马尼亚、斯洛伐克和西班牙的一个队列的医护工作者（HCWs）。我们分析了七类慢性病群体。我们纳入了2941名医护工作者（78.5％女性，73.4％≥40岁）。6.9％的医护工作者患有多发病。每种慢性疾病的患病率在1.9％（癌症）到10.3％（过敏）之间。我们拟合了两个回归模型，一个考虑了慢性疾病群体，另一个考虑了HCWs是否患有≥2个群体的疾病。6.9％的医护工作者患有多发病，而更高的9个月后疫苗接种后的抗体水平与接种三剂疫苗（RR = 2.45，CI = 1.92-3.13）以及存在先前的COVID-19感染（RR = 2.30，CI = 2.15-2.46）显著相关。相反，较低的水平与年龄较大（RR = 0.94，CI = 0.91-0.96），距离最后一剂疫苗接种时间较长（RR = 0.95，CI = 0.94-0.96）和多发病（RR = 0.89，CI = 0.80-1.00）相关。高血压与较低的抗体水平显著相关（RR = 0.87，CI = 0.80-0.95）。在多发病个体中，疫苗的血清学应答更不足够。

Understanding antibody persistence concerning multimorbidity is crucial for vaccination policies. Our goal is to assess the link between multimorbidity and serological response to SARS-CoV-2 nine months post-first vaccine. We analyzed Healthcare Workers (HCWs) from three cohorts from Italy, and one each from Germany, Romania, Slovakia, and Spain. Seven groups of chronic diseases were analyzed. We included 2941 HCWs (78.5% female, 73.4% ≥ 40 years old). Multimorbidity was present in 6.9% of HCWs. The prevalence of each chronic condition ranged between 1.9% (cancer) to 10.3% (allergies). Two regression models were fitted, one considering the chronic conditions groups and the other considering whether HCWs had diseases from ≥2 groups. Multimorbidity was present in 6.9% of HCWs, and higher 9-months post-vaccine anti-S levels were significantly associated with having received three doses of the vaccine (RR = 2.45, CI = 1.92-3.13) and with having a prior COVID-19 infection (RR = 2.30, CI = 2.15-2.46). Conversely, lower levels were associated with higher age (RR = 0.94, CI = 0.91-0.96), more time since the last vaccine dose (RR = 0.95, CI = 0.94-0.96), and multimorbidity (RR = 0.89, CI = 0.80-1.00). Hypertension is significantly associated with lower anti-S levels (RR = 0.87, CI = 0.80-0.95). The serological response to vaccines is more inadequate in individuals with multimorbidity.