MMWR Morb Mortal Wkly Rep. 2022 Jan 14;71(2):52-58. doi: 10.15585/mmwr.mm7102e1.
Multisystem inflammatory syndrome in children (MIS-C) is a severe postinfectious hyperinflammatory condition, which generally occurs 2-6 weeks after a typically mild or asymptomatic infection with SARS-CoV-2, the virus that causes COVID-19 (1-3). In the United States, the BNT162b2 (Pfizer-BioNTech) COVID-19 vaccine is currently authorized for use in children and adolescents aged 5-15 years under an Emergency Use Authorization and is fully licensed by the Food and Drug Administration for persons aged ≥16 years (4). Prelicensure randomized trials in persons aged ≥5 years documented high vaccine efficacy and immunogenicity (5), and real-world studies in persons aged 12-18 years demonstrated high vaccine effectiveness (VE) against severe COVID-19 (6). Recent evidence suggests that COVID-19 vaccination is associated with lower MIS-C incidence among adolescents (7); however, VE of the 2-dose Pfizer-BioNTech regimen against MIS-C has not been evaluated. The effectiveness of 2 doses of Pfizer-BioNTech vaccine received ≥28 days before hospital admission in preventing MIS-C was assessed using a test-negative case-control design among hospitalized patients aged 12-18 years at 24 pediatric hospitals in 20 states** during July 1-December 9, 2021, the period when most MIS-C patients could be temporally linked to SARS-CoV-2 B.1.617.2 (Delta) variant predominance. Patients with MIS-C (case-patients) and two groups of hospitalized controls matched to case-patients were evaluated: test-negative controls had at least one COVID-19-like symptom and negative SARS-CoV-2 reverse transcription-polymerase chain reaction (RT-PCR) or antigen-based assay results, and syndrome-negative controls were hospitalized patients without COVID-19-like illness. Among 102 MIS-C case-patients and 181 hospitalized controls, estimated effectiveness of 2 doses of Pfizer-BioNTech vaccine against MIS-C was 91% (95% CI = 78%-97%). All 38 MIS-C patients requiring life support were unvaccinated. Receipt of 2 doses of the Pfizer-BioNTech vaccine is associated with a high level of protection against MIS-C in persons aged 12-18 years, highlighting the importance of vaccination among all eligible children.
儿童多系统炎症综合征（MIS-C）是一种严重的感染后过度炎症性疾病，通常在感染 SARS-CoV-2 后 2-6 周出现，SARS-CoV-2 是导致 COVID-19 的病毒（1-3）。在美国，BNT162b2（辉瑞-生物科技）COVID-19 疫苗目前根据紧急使用授权在 5-15 岁儿童和青少年中使用，并由食品和药物管理局完全许可用于≥16 岁的人群（4）。在≥5 岁的人群中进行的上市前随机试验证明了疫苗的高疗效和免疫原性（5），在 12-18 岁的人群中进行的真实世界研究表明，该疫苗对严重 COVID-19 的有效性（VE）很高（6）。最近的证据表明，COVID-19 疫苗接种与青少年中 MIS-C 的发病率较低有关（7）；然而，尚未评估 2 剂辉瑞-生物科技方案对 MIS-C 的 VE。在 2021 年 7 月 1 日至 12 月 9 日期间，在 20 个州的 24 家儿童医院对 12-18 岁住院患者进行了一项病例对照研究，评估了≥28 天前接受 2 剂辉瑞-生物科技疫苗接种在预防 MIS-C 方面的有效性，当时大多数 MIS-C 患者都与 SARS-CoV-2 B.1.617.2（Delta）变体流行有关。根据研究，对患有 MIS-C（病例患者）和两组与病例患者相匹配的住院对照组进行了评估：阴性对照病例至少有一种 COVID-19 样症状且 SARS-CoV-2 逆转录-聚合酶链反应（RT-PCR）或抗原检测结果为阴性，阴性综合征对照是没有 COVID-19 样疾病的住院患者。在 102 例 MIS-C 病例患者和 181 例住院对照组中，估计 2 剂辉瑞-生物科技疫苗对 MIS-C 的有效性为 91%（95%CI=78%-97%）。所有 38 例需要生命支持的 MIS-C 患者均未接种疫苗。在 12-18 岁的人群中，接种 2 剂辉瑞-生物科技疫苗与 MIS-C 的高度保护相关，这凸显了所有符合条件的儿童接种疫苗的重要性。
