本研究旨在探究接种新冠灭活疫苗对老年奥密克戎变异株感染者临床结局和预后的保护作用。回顾性纳入2022年3月20日—2022年5月6日复旦大学附属华山医院宝山院区收治的60岁以上奥密克戎感染者1 029例，其中未接种疫苗的患者643例，接种疫苗的患者386例。比较两组样本的人口学特征、临床症状、实验室指标、临床结局差异，采用多因素回归分析接种疫苗对老年患者临床结局的影响。结果显示，两组样本在年龄分层、BMI、合并糖尿病/心血管疾病或慢性肾脏病的比例、合并基础疾病数量、C反应蛋白、D-二聚体、谷丙转氨酶、肌酐、脑钠肽前体、肌钙蛋白等指标上具有统计学差异(P＜0.05)。未接种疫苗样本组发生影像学肺炎(51.6% vs 26.2%)、接受呼吸支持(包括鼻导管或面罩吸氧、高流量氧疗或无创通气、有创通气)(40.7% vs 13.5%)、有创通气或死亡(6.2% vs 0.7%)的比例显著高于接种疫苗组(P＜0.05)。多因素回归分析提示，接种疫苗能促进老年患者核酸转阴[aHR＝1.594，95%CI (1.259, 2.017)]，降低影像学肺炎[aOR＝0.501，95%CI (0.370, 0.678)]、呼吸支持[aOR＝0.336，95%CI (0.232, 0.487)]、有创通气或死亡[aOR: 0.190，95%CI (0.052, 0.687)]发生的风险。本研究通过临床数据证实，接种新冠疫苗对老年患者的临床结局和预后具有保护作用。

The purpose of the current study is to investigate the association between vaccination status and clinical outcomes in the elderly during the Omicron wave. A total of 1 029 patients aged 60 years or older were hospitalized in Huashan Hospital of Fudan University, Baoshan Campus from March 20 to May 6, 2022 (643 cases unvaccinated, 386 cases vaccinated). Demographic characteristics, clinical symptoms, laboratory findings, and clinical outcomes were compared, and multivariate regression was applied to determine association between vaccination status and clinical outcomes. Results indicated a significant difference in age, BMI, comorbidity (diabetes, cardiovascular disease, chronic kidney disease), number of comorbidities, and laboratory findings (lymphocyte counts, C-reactive protein, D-dimer, ALT, creatinine, pro-BNP and troponin) between unvaccinated and vaccinated patients (P<0.05). Unvaccinated patients were more likely to experience COVID-19-related outcomes, including pneumonia (51.6% vs 26.2%), respiratory support [40.7% vs 13.5%], invasive ventilation or death [6.2% vs 0.7%]. Multivariate regression analysis showed that vaccination was associated with early virus shedding [aHR＝1.594, 95%CI (1.259, 2.017)], and protected against progression to pneumonia [aOR＝0.501, 95%CI (0.370, 0.678)], respiratory support [aOR＝0.336, 95%CI (0.232, 0.487)], invasive ventilation or death [aOR＝0.190, 95%CI (0.052, 0.687)] in elderly patients. Our findings suggest that inactivated vaccine protects against COVID-19-related severe outcomes in individuals aged over 60 years.