Analysis of the adverse events following the mRNA-1273 COVID-19 vaccine

Objective This study aims to characterize the adverse events (AEs) following the administration of the mRNA-1273 COVID-19 vaccine from the Vaccine Adverse Event Reporting System (VAERS) data.Methods In this case/non-case analysis, reports between 1 January 2021, and 27 October 2022, were extracted from VAERS. AEs were defined as preferred terms (PTs) by Medical Dictionary for Regulatory Activities (MedDRA) terminology. Disproportionality analyses were conducted to calculate the reporting odds and proportional reporting ratios. The Bayesian approach was used to calculate information component (IC) values and Empirical Bayesian Geometric Mean scores for all the AEs detected.Results 186 MedDRA PTs compromising 702,495 AEs associated with the mRNA-1273 vaccine were identified. Three statistically significant signals were identified for general and systemic AEs, administration site conditions, and product issues. Cardiac disorders were rarely reported, the most common being; 489 reports for 'myocarditis' (19.44%), 475 for 'acute myocardial infarction' (18.88%), 457 for 'myocardial infarction' (18.16%), 290 for 'bradycardia' (11.53%) and 281 for 'pericarditis' (11.17%).Conclusions The most frequently identified AEs following mRNA-1273 vaccination agree with those listed within the Summary of Product Characteristics. In addition, disproportionality analysis did not find any statistically significant signals for myocarditis or pericarditis.