Moore Mia, Anderson Larissa, Schiffer Joshua T, Matrajt Laura, Dimitrov Dobromir
Fred Hutchinson Cancer Center, 1100 Fairview Avenue N, Seattle, WA, USA.
Fred Hutchinson Cancer Center, 1100 Fairview Avenue N, Seattle, WA, USA.
Vaccine. 2025 Apr 30;54:126966. doi: 10.1016/j.vaccine.2025.126966. Epub 2025 Mar 5.
Despite the success of mRNA vaccines, COVID-19 remains a significant public health threat. Waning of immune memory and the emergence of new variants can degrade population-level protection and contribute to ongoing morbidity.
In this systematic review and meta-regression, we searched for studies in PubMed, medRxiv and bioRxiv published January 1, 2020 - January 1, 2023 measuring vaccine effectiveness as the reduction in infection, symptomatic disease, and severe disease (resulting in hospitalization and/or death) conferred by mRNA-based vaccination and prior SARS-CoV-2 infections relative to naïve individuals. We excluded studies that did not distinguish between mRNA and non-mRNA vaccines or had less than 1000 participants. Using a multi-level model, we quantified the initial effectiveness and change over four to six months following vaccination or infection. Model covariates were COVID variant, number of vaccine doses, and the number and variant of prior infection. Our estimates were adjusted for the age of the study population.
Of 828 screened, we included 123 studies in our analysis. Vaccine effectiveness against infection and disease declined both over time and with the emergence of Omicron, regardless of booster doses, though protection against severe outcomes was more durable. Booster doses reduced severe Omicron infections by 90.5 % (95 % confidence interval 87.1-93.8) and 77.6 % (70.5-84.7) at two and 26 weeks post-vaccination, respectively. Protection conferred by hybrid immunity was more durable than that from either vaccination or prior infection alone, but protection against Omicron reinfection was only 50.1 % (32.5-67.8) at 26 weeks following vaccination. Individuals with hybrid immunity had 80.6 % protection (70.0-91.2) following booster doses declining to 36.9 % (19.3-54.6) after 16 weeks.
Our results suggest that timely deployment of pre-existing boosters can greatly mitigate seasonal COVID outbreaks even in populations with prior infection and vaccination.
Centers for Disease Control and Prevention (NU38OT000297-03).
尽管mRNA疫苗取得了成功，但新冠病毒病仍然是重大的公共卫生威胁。免疫记忆的减弱和新变种的出现会降低人群层面的保护，并导致持续发病。
在这项系统评价和meta回归分析中，我们检索了2020年1月1日至2023年1月1日期间发表在PubMed、medRxiv和bioRxiv上的研究，这些研究测量了基于mRNA的疫苗接种和既往新冠病毒2感染相对于未感染个体所带来的感染、有症状疾病和严重疾病（导致住院和/或死亡）减少情况的疫苗效力。我们排除了未区分mRNA疫苗和非mRNA疫苗或参与者少于1000人的研究。使用多层次模型，我们量化了接种疫苗或感染后最初的效力以及4至6个月内的变化。模型协变量包括新冠变种、疫苗剂量数以及既往感染的次数和变种。我们的估计针对研究人群的年龄进行了调整。
在筛选的828项研究中，我们纳入了123项研究进行分析。无论是否接种加强针，疫苗对感染和疾病的效力均随时间推移以及奥密克戎变种的出现而下降，不过对严重后果的保护更持久。接种加强针后2周和26周时，加强针分别将奥密克戎严重感染减少了90.5%（95%置信区间87.1 - 93.8）和77.6%（70.5 - 84.7）。混合免疫提供的保护比单独接种疫苗或既往感染更持久，但接种疫苗后26周时对奥密克戎再感染的保护仅为50.1%（32.5 - 67.8）。混合免疫个体在接种加强针后有80.6%的保护（70.0 - 91.2），16周后降至36.9%（19.3 - 54.6）。
我们的结果表明，即使在有既往感染和接种疫苗的人群中，及时部署现有的加强针也能极大地减轻季节性新冠疫情爆发。
疾病控制与预防中心（NU38OT000297 - 03）
