DataSheet_1_The effects of vaccination on the disease severity and factors for viral clearance and hospitalization in Omicron-infected patients: A retrospective observational cohort study from recent regional outbreaks in China.docx

ObjectThis study attempted to explore the effects of vaccination on disease severity and the factors for viral clearance and hospitalization in omicron-infected patients.
MethodsThe clinical manifestations of 3,265 Omicron-infected patients (BA.2 lineage variant; the Omicron group) were compared with those of 226 Delta-infected patients (the Delta group). A Multi-class logistic regression model was employed to analyze the impacts of vaccination doses and intervals on disease severity; a logistic regression model to evaluate the risk factors for hospitalization; R 4.1.2 data analysis to investigate the factors for time for nucleic acid negativization (NAN).
ResultsCompared with the Delta group, the Omicron group reported a fast transmission, mild symptoms, and lower severity incidence, and a significant inverse correlation of vaccination dose with clinical severity (OR: 0.803, 95%CI: 0.742-0.868, p<0.001). Of the 7 or 5 categories of vaccination status, the risk of severity significantly decreased only at ≥21 days after three doses (OR: 0.618, 95% CI: 0.475-0.803, p<0.001; OR: 0.627, 95% CI: 0.482-0.815, p<0.001, respectively). The Omicron group also reported underlying illness as an independent factor for hospitalization, sore throat as a protective factor, and much shorter time for NAN [15 (12,19) vs. 16 (12,22), p<0.05]. NAN was associated positively with age, female gender, fever, cough, and disease severity, but negatively with vaccination doses.
ConclusionBooster vaccination should be advocated for COVID-19 pandemic-related control and prevention policies and adequate precautions should be taken for patients with underlying conditions.

研究目的：本研究旨在探讨疫苗接种对奥密克戎（Omicron）感染者疾病严重程度的影响，以及奥密克戎感染患者的病毒清除与住院相关影响因素。
方法：纳入3265例奥密克戎BA.2亚型感染者作为奥密克戎组，226例德尔塔（Delta）感染者作为德尔塔组，对比两组患者的临床表现。采用多分类logistic回归模型分析疫苗接种剂次与间隔时间对疾病严重程度的影响；采用logistic回归模型评估患者住院的危险因素；使用R 4.1.2软件开展数据分析，探究核酸转阴时间（nucleic acid negativization, NAN）的影响因素。
结果：与德尔塔组相比，奥密克戎组传播速度更快、症状更轻微，严重程度发生率更低；疫苗接种剂次与临床严重程度呈显著负相关（OR=0.803，95%CI：0.742~0.868，p<0.001）。在7类及5类疫苗接种状态分层中，仅在接种3剂次后≥21天时，疾病严重程度风险显著降低（分别为OR=0.618，95%CI：0.475~0.803，p<0.001；OR=0.627，95%CI：0.482~0.815，p<0.001）。奥密克戎组中，基础疾病为患者住院的独立危险因素，咽痛为保护因素，且核酸转阴时间更短[15(12,19) vs 16(12,22)，p<0.05]。核酸转阴时间与年龄、女性性别、发热、咳嗽及疾病严重程度呈正相关，与疫苗接种剂次呈负相关。
结论：应在新型冠状病毒肺炎（COVID-19）疫情防控政策中倡导加强针接种，并为存在基础疾病的患者采取充分的防护措施。