Law Martin, Ho Sam S H, Tsang Gigi K C, Ho Clarissa M Y, Kwan Christine M, Yan Vincent Ka Chun, Yiu Hei Hang Edmund, Lai Francisco Tsz Tsun, Wong Ian Chi Kei, Chan Esther Wai Yin
Li Ka Shing Faculty of Medicine, Department of Pharmacology and Pharmacy, Centre for Safe Medication Practice and Research, The University of Hong Kong, Hong Kong SAR, China.
Laboratory of Data Discovery for Health (D4H), Hong Kong Science and Technology Park, Hong Kong SAR, China.
Lancet Reg Health West Pac. 2023 May 20;37:100788. doi: 10.1016/j.lanwpc.2023.100788.
Inactivated, whole-virion vaccines have been used extensively in the SARS-CoV-2 pandemic. Its efficacy and effectiveness across regions have not been systematically evaluated. Efficacy refers to how well a vaccine performs in a controlled environment. Effectiveness refers to how well it performs in real world settings.
This systematic review and meta-analysis reviewed published, peer-reviewed evidence on all WHO-approved inactivated vaccines and evaluated their efficacy and effectiveness against SARS-CoV-2 infection, symptomatic infection, severe clinical outcomes, and severe COVID-19. We searched Pubmed (including MEDLINE), EMBASE (via OVID), Web of Science Core Collection, Web of Science Chinese Science Citation Database, and Clinicaltrials.gov.
The final pool included 28 studies representing over 32 million individuals reporting efficacy or effectiveness estimates of complete vaccination using any approved inactivated vaccine between January 1, 2019 and June 27, 2022. Evidence was found for efficacy and effectiveness against symptomatic infection (OR 0.21, 95% CI 0.16-0.27, I = 28% and OR 0.32, 95% CI 0.16-0.64, I = 98%, respectively) and infection (OR 0.53, 95% CI 0.49-0.57, I = 90% and OR 0.31, 95% CI 0.24-0.41, I = 0%, respectively) for early SARS-CoV-2 variants of concern (VoCs) (Alpha, Delta), and for waning of vaccine effectiveness with more recent VoCs (Gamma, Omicron). Effectiveness remained robust against COVID-related ICU admission (OR 0.21, 95% CI 0.04-1.08, I = 99%) and death (OR 0.08, 95% CI 0.00-2.02, I = 96%), although effectiveness estimates against hospitalization (OR 0.44, 95% CI 0.37-0.53, I = 0%) were inconsistent.
This study showed evidence of efficacy and effectiveness of inactivated vaccines for all outcomes, although inconsistent reporting of key study parameters, high heterogeneity of observational studies, and the small number of studies of particular designs for most outcomes undermined the reliability of the findings. Findings highlight the need for additional research to address these limitations so that more definitive conclusions can be drawn to inform SARS-CoV-2 vaccine development and vaccination policies.
Health and Medical Research Fund on COVID-19, Health Bureau of the Government of the Hong Kong SAR.
在新冠疫情期间，灭活全病毒疫苗得到了广泛应用。其在不同地区的有效性和实际效果尚未得到系统评估。有效性是指疫苗在受控环境中的表现，实际效果则指疫苗在现实环境中的表现。
本系统评价和荟萃分析回顾了所有世界卫生组织批准的灭活疫苗的已发表、经同行评审的证据，并评估了它们对新冠病毒感染、有症状感染、严重临床结局和重症新冠肺炎的有效性和实际效果。我们检索了PubMed（包括MEDLINE）、EMBASE（通过OVID）、科学引文索引核心合集、中国科学引文数据库和Clinicaltrials.gov。
最终纳入了28项研究，涉及超过3200万人，报告了2019年1月1日至2022年6月27日期间使用任何批准的灭活疫苗进行全程接种后的有效性或实际效果估计值。发现针对早期值得关注的新冠病毒变异株（阿尔法、德尔塔）的有症状感染（比值比0.21，95%置信区间0.16 - 0.27，I² = 28%）和感染（比值比0.53，95%置信区间0.49 - 0.57，I² = 90%）以及针对较新变异株（伽马、奥密克戎）疫苗实际效果的减弱，均有有效性和实际效果的证据。对于与新冠相关的重症监护病房入院（比值比0.21，95%置信区间0.04 - 1.08，I² = 99%）和死亡（比值比0.08，95%置信区间0.00 - 2.02，I² = 96%），实际效果仍然显著，尽管针对住院治疗的实际效果估计值（比值比0.44，95%置信区间0.37 - 0.53，I² = 0%）并不一致。
本研究显示了灭活疫苗在所有结局方面的有效性和实际效果的证据，尽管关键研究参数的报告不一致、观察性研究的异质性高以及大多数结局的特定设计研究数量少，削弱了研究结果的可靠性。研究结果凸显了开展更多研究以解决这些局限性的必要性，以便能够得出更明确的结论，为新冠病毒疫苗研发和疫苗接种政策提供参考。
香港特别行政区政府卫生署新冠疫情健康及医学研究基金。
