Hua Qiaoli, Zheng Danwen, Yu Bo, Tan Xinghua, Chen Qiumin, Wang Longde, Zhang Jing, Liu Yuntao, Weng Heng, Cai Yihang, Xu Xiaohua, Feng Bing, Zheng Guangjuan, Ding Banghan, Guo Jianwen, Zhang Zhongde
The Second Clinical College, Guangzhou University of Chinese Medicine, Guangzhou 510006, China.
Department of Emergency, the Second Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou 510120, China.
Vaccines (Basel). 2022 Oct 19;10(10):1753. doi: 10.3390/vaccines10101753.
Real-world evidence on the effectiveness of inactivated vaccines against the Delta and Omicron (BA.2.38) variants remains scarce.
A retrospective cohort study was conducted to estimate the adjusted vaccine effectiveness (aVE) of one, two, and three doses of inactivated vaccines in attenuating pneumonia, severe COVID-19, and the duration of viral shedding in Delta and Omicron cases using modified Poisson and linear regression as appropriate.
A total of 561 COVID-19 cases were included (59.2% Delta and 40.8% Omicron). In total, 56.4% (184) of Delta and 12.0% (27) of Omicron cases had COVID-19 pneumonia. In the two-dose vaccinated population, 1.4% of Delta and 89.1% of Omicron cases were vaccinated for more than 6 months. In Delta cases, the two-dose aVE was 52% (95% confidence interval, 39-63%) against pneumonia and 61% (15%, 82%) against severe disease. Two-dose vaccination reduced the duration of viral shedding in Delta cases, but not in booster-vaccinated Omicron cases. In Omicron cases, three-dose aVE was 68% (18%, 88%) effective against pneumonia, while two-dose vaccination was insufficient for Omicron. E-values were calculated, and the E-values confirmed the robustness of our findings.
In Delta cases, two-dose vaccination within 6 months reduced pneumonia, disease severity, and the duration of viral shedding. Booster vaccination provided a high level of protection against pneumonia with Omicron and should be prioritized.
关于灭活疫苗对德尔塔和奥密克戎（BA.2.38）变异株有效性的真实世界证据仍然匮乏。
进行了一项回顾性队列研究，以使用修正泊松回归和线性回归（视情况而定）来估计一剂、两剂和三剂灭活疫苗在减轻德尔塔和奥密克戎病例的肺炎、重症新冠病毒疾病以及病毒脱落持续时间方面的调整后疫苗有效性（aVE）。
共纳入561例新冠病毒疾病病例（59.2%为德尔塔变异株，40.8%为奥密克戎变异株）。总体而言，56.4%（184例）的德尔塔病例和12.0%（27例）的奥密克戎病例患有新冠病毒肺炎。在接种两剂疫苗的人群中，1.4%的德尔塔病例和89.1%的奥密克戎病例接种疫苗超过6个月。在德尔塔病例中，两剂疫苗预防肺炎的aVE为52%（95%置信区间，39 - 63%），预防重症疾病的aVE为61%（15%，82%）。两剂疫苗接种减少了德尔塔病例的病毒脱落持续时间，但在接种加强针的奥密克戎病例中未减少。在奥密克戎病例中，三剂疫苗预防肺炎的aVE为68%（18%，88%），而两剂疫苗接种对奥密克戎变异株不足。计算了E值，E值证实了我们研究结果的稳健性。
在德尔塔病例中，6个月内接种两剂疫苗可减轻肺炎、疾病严重程度并缩短病毒脱落持续时间。加强针接种对奥密克戎变异株肺炎提供了高水平保护，应优先考虑。
