Medical Department, Sanofi Vaccines, Lyon, France.
Medical Department, Sanofi Vaccines, Lyon, France.
Clin Microbiol Infect. 2024 Dec;30(12):1592-1598. doi: 10.1016/j.cmi.2024.08.012. Epub 2024 Aug 24.
High-dose quadrivalent influenza vaccine (HD-QIV) was introduced during the 2021/2022 influenza season in France for adults aged ≥65 years as an alternative to standard-dose quadrivalent influenza vaccine (SD-QIV). The aim of this study is to estimate the relative vaccine effectiveness of HD-QIV vs. SD-QIV against influenza-related hospitalizations in France.
Community-dwelling individuals aged ≥65 years with reimbursed influenza vaccine claims during the 2021/2022 influenza season were included in the French national health insurance database. Individuals were followed up from vaccination day to 30 June 2022, nursing home admission or death date. Baseline socio-demographic and health characteristics were identified from medical records over the five previous years. Hospitalizations for influenza and other causes were recorded from 14 days after vaccination until the end of follow-up. HD-QIV and SD-QIV vaccinees were matched using 1:4 propensity score matching with an exact constraint on age group, sex, week of vaccination, and region. Incidence rate ratios were estimated using zero-inflated Poisson or zero-inflated negative binomial regression models.
We matched 405 385 HD-QIV to 1 621 540 SD-QIV vaccinees. HD-QIV was associated with a 23.3% (95% CI, 8.4-35.8) lower rate of influenza hospitalizations compared with SD-QIV (69.5/100 000 person years vs. 90.5/100 000 person years). Post-matching, we observed higher rates in the HD-QIV group for hospitalizations non-specific to influenza and negative control outcomes, suggesting residual confounding by indication.
HD-QIV was associated with lower influenza-related hospitalization rates vs. SD-QIV, consistent with existing evidence, in the context of high SARS-CoV-2 circulation in France and likely prioritization of HD-QIV for older/more comorbid individuals.
在 2021/2022 流感季，法国为年龄≥65 岁的成年人推出了高剂量四价流感疫苗（HD-QIV），作为标准剂量四价流感疫苗（SD-QIV）的替代选择。本研究旨在评估 HD-QIV 相对于 SD-QIV 对法国流感相关住院的相对疫苗有效性。
本研究纳入了在 2021/2022 流感季有报销流感疫苗的年龄≥65 岁的社区居住者。从接种日到 2022 年 6 月 30 日、疗养院入院或死亡日期对参与者进行随访。从过去 5 年的医疗记录中确定了基线社会人口统计学和健康特征。从接种后 14 天到随访结束记录流感和其他原因引起的住院情况。使用 1:4 倾向评分匹配，在年龄组、性别、接种周和地区上进行精确匹配，对 HD-QIV 和 SD-QIV 疫苗接种者进行匹配。使用零膨胀泊松或零膨胀负二项回归模型估计发病率比值。
我们匹配了 405385 例 HD-QIV 与 1621540 例 SD-QIV 疫苗接种者。与 SD-QIV 相比，HD-QIV 导致流感住院的发生率降低了 23.3%（95%CI，8.4-35.8）（69.5/100000 人年 vs. 90.5/100000 人年）。匹配后，我们观察到 HD-QIV 组非特异性流感和阴性对照结果的住院率更高，表明存在残余混杂偏倚。
在法国 SARS-CoV-2 传播率较高的背景下，HD-QIV 与 SD-QIV 相比，与现有证据一致，与流感相关的住院率较低，这可能表明 HD-QIV 优先用于年龄较大/合并症较多的人群。
