Background The purpose of this study was to evaluate whether the 2023-2024 formulation of the COVID-19 mRNA vaccine protects against COVID-19. Methods Employees of Cleveland Clinic in employment when the 2023-2024 formulation of the COVID-19 mRNA vaccine became available to employees, were included. Cumulative incidence of COVID-19 over the following 17 weeks was examined prospectively. Protection provided by vaccination (analyzed as a time-dependent covariate) was evaluated using Cox proportional hazards regression, with time-dependent coefficients used to separate effects before and after the JN.1 lineage became dominant. The analysis was adjusted for the propensity to get tested, age, sex, pandemic phase when the last prior COVID-19 episode occurred, and the number of prior vaccine doses. Results Among 48210 employees, COVID-19 occurred in 2462 (5.1%) during the 17 weeks of observation. In multivariable analysis, the 2023-2024 formula vaccinated state was associated with a significantly lower risk of COVID-19 before the JN.1 lineage became dominant (HR, .58; 95% C.I., .49-.68, p-value < .001), and lower risk but one that did not reach statistical significance after (HR, .81; 95% C.I., .65-1.01, p-value 0.06). Estimated vaccine effectiveness (VE) was 42% (95% C.I., 32%-51%) before the JN.1 lineage became dominant, and 19% (C.I., -1%-35%) after. Risk of COVID-19 was lower among those previously infected with an XBB or more recent lineage, and increased with the number of vaccine doses previously received. Conclusions The 2023-2024 formula COVID-19 vaccine given to working-aged adults afforded modest protection overall against COVID-19 before the JN.1 lineage became dominant, and less protection after.

中文翻译：

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2023-2024年制剂2019冠状病毒mRNA疫苗的有效性

背景 本研究的目的是评估 2023-2024 年 COVID-19 mRNA 疫苗配方是否可以预防 COVID-19。方法 包括当 2023-2024 年 COVID-19 mRNA 疫苗制剂可供员工使用时克利夫兰诊所在职的员工。对接下来 17 周内 COVID-19 的累积发病率进行了前瞻性检查。使用 Cox 比例风险回归评估疫苗接种提供的保护（分析为时间依赖性协变量），并使用时间依赖性系数来区分 JN.1 谱系占主导地位之前和之后的影响。该分析根据接受检测的倾向、年龄、性别、上次发生 COVID-19 事件时的大流行阶段以及之前接种的疫苗剂量进行了调整。结果 在 17 周的观察期间，在 48210 名员工中，有 2462 名员工 (5.1%) 感染了 COVID-19。在多变量分析中，在 JN.1 谱系占主导地位之前，2023-2024 年配方疫苗接种状态与显着较低的 COVID-19 风险相关（HR，0.58；95% CI，0.49-0.68，p 值 < ; .001），风险较低，但之后未达到统计学显着性（HR，.81；95% CI，.65-1.01，p 值 0.06）。在 JN.1 谱系成为主导之前，估计的疫苗有效性 (VE) 为 42% (95% CI, 32%-51%)，之后为 19% (CI, -1%-35%)。之前感染过 XBB 或更近的血统的人感染 COVID-19 的风险较低，并且随着之前接种疫苗剂量的增加而增加。结论 在 JN.1 谱系成为主导之前，为工作年龄成年人接种的 2023-2024 年配方 COVID-19 疫苗对 COVID-19 提供了适度的总体保护，而在 JN.1 谱系成为主导之后提供的保护较少。