Hyper inflammatory syndrome following COVID-19 mRNA vaccine in children: A national post-authorization pharmacovigilance study.

Background

Multisystem inflammatory syndrome in children (MIS-C) is the most severe clinical entity associated with pediatric SARS-CoV-2 infection with a putative role of the spike protein into the immune system activation. Whether COVID-19 mRNA vaccine can induce this complication in children is unknown. We aimed to assess the risk of hyper-inflammatory syndrome following COVID-19 mRNA vaccine in children.

Methods

We conducted a post-authorization national population-based surveillance using the French enhanced pharmacovigilance surveillance system for COVID-19 vaccines. All cases of suspected hyper-inflammatory syndrome following COVID-19 mRNA vaccine in 12-17-year-old children between June 15

Findings

Up to January 2022, 8,113,058 COVID-19 mRNA vaccine doses were administered to 4,079,234 12-17-year-old children. Among them, 12 presented a hyper-inflammatory syndrome with multisystemic involvement. Main clinical features included male predominance (10/12, 83%), cardiac involvement (10/12, 83%), digestive symptoms (10/12, 83%), coagulopathy (7/12, 58%), cytolytic hepatitis (6/12, 50%), and shock (5/12, 42%). 4/12 (33%) required intensive care unit transfer, and 3/12 (25%) hemodynamic support. All cases recovered. In eight cases, no evidence of previous SARS-CoV-2 infection was found. The reporting rate was 1.5 (95%CI [0.8; 2.6]) per 1,000,000 doses injected, i.e. 2.9 (95%CI [1.5; 5.1]) per 1,000,000 12-17-year-old vaccinated children. As a comparison, 113 MIS-C (95%CI [95; 135]) occurred per 1,000,000 12-17-year-old children infected by SARS-CoV-2.

Interpretation

Very few cases of hyper-inflammatory syndrome with multi-organ involvement occurred following COVID-19 mRNA vaccine in 12-17-year-old children. The low reporting rate of this syndrome, compared to the rate of post-SARS-CoV-2 MIS-C in the same age-group, largely supports the vaccination in a context of an important circulation of SARS-CoV-2.

Funding

ESPID Fellowship Award; Grandir-Fonds de Solidarité Pour L'enfance.

Informations de copyright

© 2022 The Authors.

Déclaration de conflit d'intérêts

Dr N. Ouldali reports travel grants from GSK, Pfizer, and Sanofi. Dr C. Levy reported receiving grants from Pfizer and personal fees from Pfizer and Merck. Pr R. Cohen reported receiving personal fees from GlaxoSmithKline, Pfizer, Sanofi, and Merck Sharp & Dohme. Dr V. Hentgen reports travel grants from Novartis and Sobi. Pr F. Angoulvant reports receiving personal fees from MSD, Astrazeneca, Sanofi and Pfizer. Pr A. Belot reports receiving personal fees from GlaxoSmithKline, Novartis, Sobi and Pfizer, and grants from Merck Serono and Boehringer Ingelheim. All other authors have no potential conflicts of interest to disclose.