Fama Federico, Fattore Rebecca, Raimondo Paolo, Brivio Fabio, Holmes Darcy, Muheberimana Toussaint, Nayfeh Tarek, Bandera Alessandra, Gori Andrea, Passerini Matteo, Colaneri Marta
Department of Infectious Diseases, Luigi Sacco University Hospital, Milan, Italy.
Centre for Multidisciplinary Research in Health Science (MACH), University of Milan, Milan, Italy.
Front Med (Lausanne). 2025 Aug 14;12:1624459. doi: 10.3389/fmed.2025.1624459. eCollection 2025.
Synthesizing data from existing literature is crucial for validating the robustness of associations, assessing data quality, and forming recommendations, especially given the vast amount of information available on SARS-CoV-2. This study aims to conduct an overview of reviews to evaluate the strength and validity of associations between VOCs and specific clinical outcomes in COVID-19 patients.
An overview of reviews according to the principles of PRIOR protocol was performed searching multiple databases in January 2024 and an updated search was conducted in MEDLINE database in June 2025. Peer reviewed systematic reviews considering two or more VOCs and reporting on clinical outcomes such as mortality, hospitalization, severe disease, admission to ICU, and mechanical ventilation were included. Data on study population and measures of association between clinical outcome and VOCs were considered. The quality of the studies was assessed through the AMSTAR-2 tool. Effect sizes and confidence intervals for each association between VOCs and clinical outcomes were reported. Subgroup analyses were performed where feasible. A citation matrix was used to assess the overlap between the included systematic reviews.
Twelve studies were included in the review, with a total of 24 comparisons, primarily between Omicron and Delta variants (19/24). Omicron was consistently associated with better clinical outcomes compared to Delta. The confidence in the results of 10/12 studies was rated critically low. The overlap between the included reviews was minimal, with 10% having significant overlap (>15%).
Our overview of reviews shows the lower hazard on human health of the Omicron compared to Delta variant. However, the quality of the reviews included was generally low, prompting the need for more rigorous systematic reviews.
This overview of reviews was registered in PROSPERO, CRD42024500841; https://www.crd.york.ac.uk/PROSPERO/display_record.php?ID=CRD42024500841.
综合现有文献数据对于验证关联的稳健性、评估数据质量以及形成建议至关重要，尤其是考虑到关于严重急性呼吸综合征冠状病毒2（SARS-CoV-2）的信息量巨大。本研究旨在对综述进行概述，以评估新型冠状病毒变异株（VOCs）与新冠肺炎患者特定临床结局之间关联的强度和有效性。
根据PRIOR方案的原则进行综述概述，于2024年1月检索多个数据库，并于2025年6月在MEDLINE数据库中进行更新检索。纳入经过同行评审的系统综述，这些综述考虑了两种或更多种VOCs，并报告了诸如死亡率、住院率、重症疾病、入住重症监护病房（ICU）以及机械通气等临床结局。考虑了研究人群的数据以及临床结局与VOCs之间的关联度量。通过AMSTAR-2工具评估研究质量。报告了每种VOCs与临床结局之间关联的效应大小和置信区间。在可行的情况下进行亚组分析。使用引用矩阵评估纳入的系统综述之间的重叠情况。
该综述纳入了12项研究，总共进行了24项比较，主要是在奥密克戎变异株和德尔塔变异株之间（19/24）。与德尔塔变异株相比，奥密克戎变异株始终与更好的临床结局相关。12项研究中有10项研究结果的可信度被评为极低。纳入综述之间的重叠极少，只有10%存在显著重叠（>15%）。
我们的综述概述表明，与德尔塔变异株相比，奥密克戎变异株对人类健康的危害更低。然而，纳入综述的质量普遍较低，这促使需要进行更严格的系统综述。
本综述概述已在国际前瞻性系统综述注册库（PROSPERO）注册，注册号为CRD42024500841；https://www.crd.york.ac.uk/PROSPERO/display_record.php?ID=CRD42024500841 。
