key: cord-0841357-qq1bkx28 authors: Foltran, Déborah; Delmas, Clément; Flumian, Clara; De Paoli, Pierre; Salvo, Francesco; Gautier, Sophie; Drici, Milou-Daniel; Karsenty, Clément; Montastruc, François title: Myocarditis and Pericarditis in Adolescents after First and Second doses of mRNA COVID-19 Vaccines date: 2021-11-26 journal: Eur Heart J Qual Care Clin Outcomes DOI: 10.1093/ehjqcco/qcab090 sha: 780509cf25a8fededfe6bd958a52542024367082 doc_id: 841357 cord_uid: qq1bkx28 nan and/or myocarditis with mRNA COVID-19 vaccines. 2, 3 In August 2021, the US Centers for Disease Control and Prevention (CDC) published data suggesting a higher rate of vaccinationrelated myocarditis in young men, but no stratification was made on adolescent age group. 4 Recently, 2 two observational studies from Israel estimated the incidence of myocarditis around 0.64 and 1.42 per 100,000 persons after the first dose of Tozinameran and 3.83 per 100,000 after the second dose. 5, 6 The risk difference between the first and second doses of We included all reports registered between January 1, 2021, and September 14, 2021, with age and sex known. All adolescents (12-17 years) who received mRNA COVID-19 vaccines were included. As the reports from US did not include dose information (first or second dose), we have excluded these data from the study. All reports were reviewed by authors (DF, CF, PDP) including one clinical cardiologist (DF) and were classified in reports related to first dose (D1), second dose (D2) or non-available information (NA). Performing disproportionality analyses, we compared the cases of pericarditis and/or myocarditis in patients exposed to the second dose of mRNA COVID-19 vaccines with those reported in cases (62%). The most frequent co-reported symptoms were chest pain, pyrexia or dyspnea. The time onset was 4 days for D1 and 3 days for D2 (3 days for NA) (Figure 1) . Compared with the first dose of mRNA COVID-19 vaccines, the second dose was associated with an increased risk of reporting pericarditis and/or myocarditis (ROR 4.95; 95%CI 3.14, 7.89) (Figure 2 This study evaluated more than 4,900 adverse effects of mRNA COVID-19 vaccines in adolescents mainly reported by European countries. We found that the second dose of vaccine was associated with a 5-fold increase in the reporting odds of myocarditis and/or pericarditis compared to first dose of vaccine. This risk was higher in boys particularly for myocarditis. Our results suggest no differences according age group or type of vaccine. As the US pharmacovigilance data did not include dose information (dose 1 or dose 2), we were unable to analyze the reports. This lack of information is a potential limitation of our study on All authors conceived and designed the study. FM and CF acquired the data and did the statistical analyses. All authors analyzed and interpreted the data. DF wrote the manuscript, and all authors critically revised the manuscript. FM supervised the study and is the guarantor. All authors approved the final version of the manuscript and are accountable for its accuracy. Abbreviations: CI, confidence interval; ROR, reporting odds ratio. D1, first dose, D2, second dose, NA, information relative to the dose not available † We used the case non-case method which is similar to case-control studies but adapted for pharmacovigilance studies. We used reporting odds ratios (ROR) and their 95% confidence interval (95% CI) to calculate disproportionality. ROR is a ratio similar in concept to the odds ratio in case-control studies and corresponds to the exposure odds among reported cases of myocarditis/pericarditis over the exposure odds among reported non-case. Cases were reports containing any terms including the terminology "Noninfectious Pericarditis" or "Non-infectious Myocarditis" found in MedDRA dictionary. Non-cases were all other reports recorded in VigiBase® during the same period of interest for our population. The logistic regression model performed for the disproportionality analysis was adjusted for 5 variables: age, sex, type of reporter (physician or other), completeness of individual case safety reports (high or low), and number of co-reported drugs (none, one or two, or more than two) when the headcount allowed it. Berar Yanay N. Myocarditis following COVID-19 mRNA vaccination Myocarditis and Pericarditis After Vaccination for COVID-19 Comirnaty and Spikevax: possible link to very rare cases of myocarditis pericarditis Presentation Slides | Immunization Practices | CDC Myocarditis after Covid-19 Vaccination in a Large Health Care Organization The authors acknowledge the Uppsala Monitoring Centre (UMC) who provided and gave permission to use the data analyzed in the present study. Access to the World Health Organization global individual case safety report database, VigiBase®, is available without fees by Dr. Montastruc. The authors are indebted to the National Pharmacovigilance Centers that contributed data. The opinions and conclusions in this study are not necessarily those of the various centers or of the World Health Organization. The data underlying this article will be shared on reasonable request to the corresponding author Conflict of Interest Disclosures: All authors have no conflicts to disclose.