Myocarditis is a recognized safety concern following COVID-19 mRNA vaccination. However, there is limited research quantifying the risk associated with the third dose or comparing the risk between the three doses. The US Vaccine Adverse Event Reporting System (VAERS) is a passive surveillance system that monitors rare adverse events after US-licensed vaccination. However, studies analyzing VAERS data have often faced criticism for underreporting cases and lacking a control group to assess the increase in baseline risk.

中文翻译：

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2020-2022 年美国接种三剂 COVID-19 mRNA 疫苗后发生心肌炎的风险：一项自我对照病例系列研究

心肌炎是 COVID-19 mRNA 疫苗接种后公认的安全问题。然而，量化与第三剂相关的风险或比较三剂之间的风险的研究有限。美国疫苗不良事件报告系统 (VAERS) 是一个被动监测系统，用于监测美国许可的疫苗接种后罕见的不良事件。然而，分析 VAERS 数据的研究经常因漏报病例和缺乏对照组来评估基线风险的增加而受到批评。