Public Health Ontario, Toronto, Ontario, Canada.
Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada.
JAMA Pediatr. 2023 Apr 1;177(4):410-418. doi: 10.1001/jamapediatrics.2022.6166.
The risk of myocarditis or pericarditis after COVID-19 messenger RNA vaccines varies by age and sex, and there is some evidence to suggest increasing risk with shorter intervals between dose 1 and 2 (ie, interdose interval).
To estimate the incidence of reported myocarditis or pericarditis after BNT162b2 vaccine among adolescents and to describe the clinical information associated with these events.
DESIGN, SETTING, AND PARTICIPANTS: This was a population-based cohort study using passive vaccine safety surveillance data linked to the provincial COVID-19 vaccine registry. Included in the study were all adolescents aged 12 to 17 years in Ontario, Canada, who received 1 or more doses of BNT162b2 vaccine between December 14, 2020, and November 21, 2021, and reported an episode of myocarditis or pericarditis. Data were analyzed from December 15, 2021, to April 22, 2022.
Receipt of BNT162b2 (Comirnaty [Pfizer-BioNTech]) vaccine.
Reported incidence of myocarditis or pericarditis meeting level 1 to 3 of the Brighton Collaboration case definition per 100 000 doses of BNT162b2 administered by age group (12-15 years vs 16-17 years), sex, dose number, and interdose interval. All clinical information associated with symptoms, health care usage, diagnostic test results, and treatment at the time of the acute event were summarized.
There were approximately 1.65 million doses of BNT162b2 administered and 77 reports of myocarditis or pericarditis among those aged 12 to 17 years, which met the inclusion criteria during the study period. Of the 77 adolescents (mean [SD] age, 15.0 [1.7] years; 63 male individuals [81.8%]), 51 (66.2%) developed myocarditis or pericarditis after dose 2 of BNT162b2. Overall, 74 individuals (96.1%) with an event were assessed in the emergency department, and 34 (44.2%) were hospitalized (median [IQR] length of stay, 1 [1-2] day). The majority of adolescents (57 [74.0%]) were treated with nonsteroidal anti-inflammatory drugs only, and 11 (14.3%) required no treatment. The highest reported incidence was observed among male adolescents aged 16 to 17 years after dose 2 (15.7 per 100 000; 95% CI, 9.7-23.9). Among those aged 16 to 17 years, the reporting rate was highest in those with a short (ie, ≤30 days) interdose interval (21.3 per 100 000; 95% CI, 11.0-37.2).
Results of this cohort study suggest that there was variation in the reported incidence of myocarditis or pericarditis after BNT162b2 vaccine among adolescent age groups. However, the risk of these events after vaccination remains very rare and should be considered in relation to the benefits of COVID-19 vaccination.
COVID-19 信使 RNA 疫苗接种后心肌炎或心包炎的风险因年龄和性别而异，并且有一些证据表明，第 1 剂和第 2 剂之间的间隔较短（即间隔时间）时风险增加。
估计 BNT162b2 疫苗接种后青少年报告的心肌炎或心包炎的发生率，并描述与这些事件相关的临床信息。
设计、地点和参与者：这是一项基于人群的队列研究，使用被动疫苗安全监测数据与省级 COVID-19 疫苗登记处相关联。研究包括安大略省所有 12 至 17 岁的青少年，他们在 2020 年 12 月 14 日至 2021 年 11 月 21 日之间接受了 1 剂或多剂 BNT162b2 疫苗，并报告了心肌炎或心包炎发作。数据分析于 2021 年 12 月 15 日至 2022 年 4 月 22 日进行。
接受 BNT162b2（Comirnaty [Pfizer-BioNTech]）疫苗。
根据年龄组（12-15 岁与 16-17 岁）、性别、剂量数和间隔时间，每 10 万剂 BNT162b2 给药后报告的心肌炎或心包炎的发病率，符合布莱顿合作组织病例定义的 1 级至 3 级。总结了与症状、医疗保健使用、诊断性检查结果和急性事件时治疗相关的所有临床信息。
大约有 1650 万剂 BNT162b2 给药，在研究期间，12 至 17 岁的青少年中有 77 例符合纳入标准的心肌炎或心包炎报告。在 77 名青少年（平均[标准差]年龄，15.0[1.7]岁；63 名男性个体[81.8%]）中，51 名（66.2%）在接受 BNT162b2 第 2 剂后发生心肌炎或心包炎。总体而言，74 名（96.1%）有事件的个体在急诊科接受评估，34 名（44.2%）住院（中位数[IQR]住院时间，1[1-2]天）。大多数青少年（57 [74.0%]）仅接受非甾体抗炎药治疗，11 名（14.3%）无需治疗。在 16 至 17 岁的男性青少年中，第 2 剂后报告的发病率最高（每 100000 人中有 15.7 人；95%CI，9.7-23.9）。在 16 至 17 岁的青少年中，较短（即≤30 天）间隔时间的报告率最高（每 100000 人中有 21.3 人；95%CI，11.0-37.2）。
这项队列研究的结果表明，BNT162b2 疫苗接种后心肌炎或心包炎的报告发生率在青少年年龄组之间存在差异。然而，这些事件发生的风险仍然非常罕见，应结合 COVID-19 疫苗接种的益处来考虑。
