Boyer Christopher, Lipsitch Marc
Center for Communicable Disease Dynamics, Department of Epidemiology, Harvard T.H. Chan School of Public Health.
Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts.
Am J Epidemiol. 2024 Sep 12. doi: 10.1093/aje/kwae350.
Postexposure vaccination has the potential to prevent or modify the course of clinical disease among those exposed to a pathogen. However, due to logistical constraints, postexposure vaccine trials have been difficult to implement in practice. In place of trials, investigators have used observational data to estimate the effectiveness or optimal timing window for postexposure vaccines, but the relationship between these analyses and those that would be conducted in a trial is often unclear. Here, we define several possible target trials for postexposure vaccination and show how, under certain conditions, they can be emulated using observational data. We emphasize the importance of the incubation period and the timing of vaccination in trial design and emulation. As an example, we specify a protocol for postexposure vaccination against mpox and provide a step-by-step description of how to emulate it using data from a healthcare database or contact tracing program. We further illustrate some of the benefits of the target trial approach through simulation.
暴露后接种疫苗有可能预防或改变接触病原体者的临床疾病进程。然而，由于后勤方面的限制，暴露后疫苗试验在实际中很难实施。作为试验的替代方法，研究人员利用观察性数据来估计暴露后疫苗的有效性或最佳接种时间窗，但这些分析与在试验中进行的分析之间的关系往往不明确。在此，我们定义了几种可能的暴露后接种疫苗目标试验，并展示了在某些条件下，如何使用观察性数据对其进行模拟。我们强调潜伏期和接种时间在试验设计和模拟中的重要性。作为一个例子，我们详细说明了针对猴痘的暴露后接种疫苗方案，并逐步描述了如何使用医疗保健数据库或接触者追踪程序中的数据对其进行模拟。我们还通过模拟进一步说明了目标试验方法的一些益处。
