Mel and Enid Zuckerman College of Public Health, University of Arizona, Tucson, Arizona, USA.
National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA.
Clin Infect Dis. 2024 Jul 19;79(1):96-107. doi: 10.1093/cid/ciae130.
There are limited data on whether hybrid immunity differs by count and order of immunity-conferring events (infection with severe acute respiratory syndrome coronavirus 2 [SARS-CoV-2] or vaccination against coronavirus disease 2019 [COVID-19]). From a multi-site cohort of frontline workers, we examined the heterogeneity of the effect of hybrid immunity on SARS-CoV-2 antibody levels.
Exposures included event count and event order, categorized into 7 permutations. Outcome was level of serum antibodies against receptor-binding domain (RBD) of the ancestral SARS-CoV-2 spike protein (total RBD-binding immunoglobulin). Means were examined up to 365 days after each of the first to seventh events.
Analysis included 5793 participants measured from 7 August 2020 to 15 April 2023. Hybrid immunity from infection before 1 or 2 vaccine doses elicited modestly superior antibody responses after the second and third events (compared with infections or vaccine doses alone). This superiority was not repeated after additional events. Among adults infected before vaccination, adjusted geometric mean ratios (95% confidence interval [CI]) of anti-RBD early response (versus vaccinated only) were 1.23 (1.14-1.33), 1.09 (1.03-1.14), 0.87 (.81-.94), and 0.99 (.85-1.15) after the second to fifth events, respectively. Post-vaccination infections elicited superior responses; adjusted geometric mean ratios (95% CI) of anti-RBD early response (versus vaccinated only) were 0.93 (.75-1.17), 1.11 (1.06-1.16), 1.17 (1.11-1.24), and 1.20 (1.07-1.34) after the second to fifth events, respectively.
Evidence of heterogeneity in antibody levels by permutations of infection and vaccination history could inform COVID-19 vaccination policy.
关于混合免疫是否因免疫事件的数量和顺序而不同（感染严重急性呼吸综合征冠状病毒 2 [SARS-CoV-2] 或接种 2019 年冠状病毒病 [COVID-19] 疫苗），数据有限。本项来自一线工作者的多地点队列研究，调查了混合免疫对 SARS-CoV-2 抗体水平的影响的异质性。
暴露包括事件数量和事件顺序，分为 7 种排列。结果是针对原始 SARS-CoV-2 刺突蛋白受体结合域（RBD）的血清抗体水平（总 RBD 结合免疫球蛋白）。在每种首次到第七次事件后最多 365 天检查均值。
分析包括 2020 年 8 月 7 日至 2023 年 4 月 15 日期间测量的 5793 名参与者。感染在前两剂疫苗之前产生的混合免疫在第二次和第三次事件后引起的抗体反应略高（与单独感染或疫苗接种相比）。在额外的事件后，这种优势没有重复。在接种疫苗前感染的成年人中，与仅接种疫苗相比，早期抗 RBD 反应的调整后的几何平均比（95%置信区间 [CI]）分别为 1.23（1.14-1.33）、1.09（1.03-1.14）、0.87（0.81-0.94）和 0.99（0.85-1.15）。接种疫苗后的感染引起更高的反应；与仅接种疫苗相比，早期抗 RBD 反应的调整后的几何平均比（95%置信区间 [CI]）分别为 0.93（0.75-1.17）、1.11（1.06-1.16）、1.17（1.11-1.24）和 1.20（1.07-1.34）。
感染和疫苗接种史排列的抗体水平差异的证据可能为 COVID-19 疫苗接种政策提供信息。
