Background The extent to which infection versus vaccination has conferred similarly durable severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) immunity during the Omicron era remains unclear. Methods In a cohort of 4496 adults under continued serological surveillance throughout the first year of Omicron-predominant SARS-CoV-2 transmission, we examined incidence of new infection among individuals whose last known antigenic exposure was either recent (<90 days) or remote (≥90 days) infection or vaccination. Results We adjudicated 2053 new-onset infections occurring between 15 December 2021 through 22 December 2022. In multivariable-adjusted analyses, compared to individuals whose last known exposure was remote vaccination, those with recent vaccination (odds ratio [OR], 0.82 [95% confidence interval {CI}, .73–.93]; P = .002) or recent infection (OR, 0.14 [95% CI, .05–.45]; P = .001) had lower risk for new infection within the subsequent 90-day period. Given a significant age interaction (P = .004), we found that remote infection compared to remote vaccination was associated with significantly greater new infection risk in persons aged ≥60 years (OR, 1.88 [95% CI, 1.13–3.14]; P = .015) with no difference seen in those <60 years (1.03 [95% CI, .69–1.53]; P = .88). Conclusions During the initial year of Omicron, prior infection and vaccination both offered protection against new infection. However, remote prior infection was less protective than remote vaccination for individuals aged ≥60 years. In older adults, immunity gained from vaccination appeared more durable than immunity gained from infection.

中文翻译：

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既往感染或接种疫苗后感染严重急性呼吸系统综合症冠状病毒 2 的风险

背景 在 Omicron 时代，感染与疫苗接种在多大程度上赋予了类似的持久严重急性呼吸综合征冠状病毒 2 (SARS-CoV-2) 免疫力仍不清楚。方法 在以 Omicron 为主的 SARS-CoV-2 传播的第一年中，对 4496 名成年人进行持续血清学监测，我们检查了最近一次（<90 天）或很久以前接触过已知抗原的个体中新感染的发生率（≥90天）感染或接种疫苗。结果 我们判定了 2021 年 12 月 15 日至 2022 年 12 月 22 日期间发生的 2053 例新发感染。在多变量调整分析中，与最后一次已知暴露于远程疫苗接种的个体相比，最近接种疫苗的个体（优势比 [OR]，0.82 [95%）置信区间 {CI}, .73–.93]；P = .002) 或近期感染（OR, 0.14 [95% CI, .05–.45]；P = .001）在该时间内新感染的风险较低随后的 90 天期间。考虑到显着的年龄交互作用 (P = .004)，我们发现，与远程疫苗接种相比，远程感染与 60 岁以上人群的新感染风险显着更高相关（OR，1.88 [95% CI，1.13–3.14]；P = .015），在 60 岁以下的人群中没有观察到差异（1.03 [95% CI，0.69–1.53]；P = .88）。结论 在 Omicron 的第一年，之前的感染和疫苗接种都可以提供针对新感染的保护。然而，对于年龄 ≥ 60 岁的个体来说，较远的既往感染的保护作用不如较远的疫苗接种。在老年人中，通过疫苗接种获得的免疫力似乎比通过感染获得的免疫力更持久。