Background

Several passive surveillance systems reported increased risks of myocarditis or pericarditis, or both, after COVID-19 mRNA vaccination, especially in young men. We used active surveillance from large health-care databases to quantify and enable the direct comparison of the risk of myocarditis or pericarditis, or both, after mRNA-1273 (Moderna) and BNT162b2 (Pfizer–BioNTech) vaccinations.

Methods

We conducted a retrospective cohort study, examining the primary outcome of myocarditis or pericarditis, or both, identified using the International Classification of Diseases diagnosis codes, occurring 1–7 days post-vaccination, evaluated in COVID-19 mRNA vaccinees aged 18–64 years using health plan claims databases in the USA. Observed (O) incidence rates were compared with expected (E) incidence rates estimated from historical cohorts by each database. We used multivariate Poisson regression to estimate the adjusted incidence rates, specific to each brand of vaccine, and incidence rate ratios (IRRs) comparing mRNA-1273 and BNT162b2. We used meta-analyses to pool the adjusted incidence rates and IRRs across databases.

Findings

A total of 411 myocarditis or pericarditis, or both, events were observed among 15 148 369 people aged 18–64 years who received 16 912 716 doses of BNT162b2 and 10 631 554 doses of mRNA-1273. Among men aged 18–25 years, the pooled incidence rate was highest after the second dose, at 1·71 (95% CI 1·31 to 2·23) per 100 000 person-days for BNT162b2 and 2·17 (1·55 to 3·04) per 100 000 person-days for mRNA-1273. The pooled IRR in the head-to-head comparison of the two mRNA vaccines was 1·43 (95% CI 0·88 to 2·34), with an excess risk of 27·80 per million doses (–21·88 to 77·48) in mRNA-1273 recipients compared with BNT162b2.

Interpretation

An increased risk of myocarditis or pericarditis was observed after COVID-19 mRNA vaccination and was highest in men aged 18–25 years after a second dose of the vaccine. However, the incidence was rare. These results do not indicate a statistically significant risk difference between mRNA-1273 and BNT162b2, but it should not be ruled out that a difference might exist. Our study results, along with the benefit–risk profile, continue to support vaccination using either of the two mRNA vaccines.

Funding

US Food and Drug Administration.

中文翻译：

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美国 COVID-19 mRNA 疫苗接种后心肌炎和心包炎的风险：索赔数据库中的队列研究

背景

几个被动监测系统报告说，在接种 COVID-19 mRNA 疫苗后，心肌炎或心包炎或两者的风险增加，尤其是在年轻男性中。我们使用来自大型医疗保健数据库的主动监测来量化和直接比较 mRNA-1273 (Moderna) 和 BNT162b2 (Pfizer–BioNTech) 疫苗接种后心肌炎或心包炎或两者的风险。

方法

我们进行了一项回顾性队列研究，检查使用国际疾病分类诊断代码确定的心肌炎或心包炎或两者的主要结果，发生在疫苗接种后 1-7 天，在 18-64 岁的 COVID-19 mRNA 疫苗接种者中进行评估使用美国的健康计划索赔数据库。将观察到的 (O) 发病率与每个数据库根据历史队列估计的预期 (E) 发病率进行比较。我们使用多变量泊松回归来估计每个品牌疫苗的调整后发病率，以及比较 mRNA-1273 和 BNT162b2 的发病率比 (IRR)。我们使用荟萃分析来汇集跨数据库的调整后发病率和 IRR。

发现

在接受 16 912 716 剂 BNT162b2 和 10 631 554 剂 mRNA-1273 的 15 148 369 名年龄在 18-64 岁的人中，共观察到 411 起心肌炎或心包炎，或两者均发生。在 18-25 岁的男性中，BNT162b2 和 2·17（1· 55 至 3·04) 每 100 000 人-天的 mRNA-1273。两种 mRNA 疫苗的头对头比较中的合并 IRR 为 1·43（95% CI 0·88 至 2·34），超额风险为每百万剂 27·80（–21·88 至 2·34） 77·48) 在 mRNA-1273 受体中与 BNT162b2 相比。

解释

在 COVID-19 mRNA 疫苗接种后观察到心肌炎或心包炎的风险增加，并且在接种第二剂疫苗后在 18-25 岁的男性中风险最高。然而，这种情况很少见。这些结果并未表明 mRNA-1273 和 BNT162b2 之间存在统计学上显着的风险差异，但不应排除可能存在差异。我们的研究结果以及收益-风险概况继续支持使用两种 mRNA 疫苗中的任何一种进行疫苗接种。

资金

美国食品和药物管理局。