The COVID-19 pandemic required rapid development of vaccines within a short period of time which did not allow to assess vaccine effectiveness (VE) in the long-term. A computerized literature search was undertaken to identify eligible studies, with no language restrictions, published between 1 December 2020 and 30 June 2023. Out of a total of 27,597 publications, 761 studies were included. Early VE of 87.2% decreased to 55.1% after 9 months among populations fully immunized not only with mRNA (proxy mRNA) vaccines, and 66.3% decreased to 23.5% in populations immunized exclusively with non-mRNA vaccines. Protection against severe COVID-19 declined to 80.9% for proxy mRNA vaccines and 67.2% for non-mRNA vaccines. Omicron variants significantly diminished VE. Within 6-8 months of receiving a single booster of an mRNA vaccine, VE declined to 14.0% and 67.7% for any and severe COVID-19, respectively. Multiple mRNA booster doses restored protection that declined to 29.5% and 70.6% for any and severe COVID-19, respectively, within 5-7 months. Outcomes of this meta-regression underscore the evolving nature of COVID-19 in response to vaccination, dosing schedules, and emerging variants, and provide crucial insights for public health interventions and vaccination strategies.

中文翻译：

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了解疫苗接种后 2.5 年内 Omicron 变种激增前后针对任何严重 COVID-19 的疫苗有效性随时间变化的变化：元回归

COVID-19 大流行需要在短时间内快速开发疫苗，但无法长期评估疫苗有效性 (VE)。我们进行了计算机文献检索，以确定 2020 年 12 月 1 日至 2023 年 6 月 30 日期间发表的符合条件的研究，没有语言限制。在总共 27,597 篇出版物中，纳入了 761 项研究。在仅使用mRNA（代理mRNA）疫苗完全免疫的人群中，早期VE从87.2％下降到9个月后的55.1％，而在仅使用非mRNA疫苗免疫的人群中，早期VE从66.3％下降到23.5％。代理 mRNA 疫苗对严重 COVID-19 的保护率下降至 80.9%，非 mRNA 疫苗则下降至 67.2%。 Omicron 变体显着降低了 VE。在接受单次 mRNA 疫苗加强接种后的 6-8 个月内，任何和严重的 COVID-19 的 VE 分别下降至 14.0% 和 67.7%。多次 mRNA 加强剂量可恢复保护，在 5-7 个月内，对任何和严重的 COVID-19 的保护分别下降至 29.5% 和 70.6%。这种元回归的结果强调了 COVID-19 针对疫苗接种、给药方案和新出现的变异的不断演变的性质，并为公共卫生干预和疫苗接种策略提供了重要的见解。