Myopericarditis Associated with the Novavax COVID-19 Vaccine (NVX-CoV2373): A Retrospective Analysis of Individual Case Safety Reports from VigiBase

BACKGROUND: Myocarditis and pericarditis have been associated most notably with mRNA vaccines, but the association with a recently authorized adjuvated vaccine (NVX-CoV2373) is controversial. OBJECTIVE: The aim was to analyze the cases of myocarditis and pericarditis in association with NVX-CoV2373 reported to the World Health Organization (WHO) global database of individual case safety reports (ICSRs) for drug monitoring (VigiBase), applying disproportionality analyses. PATIENTS AND METHODS: The main characteristics of the ICSRs reporting myopericarditis with NVX-CoV2373 have been summarized. Reporting odds ratios (RORs) as a measure of disproportionality for reported myopericarditis (November 1967–August 2022) have been calculated for NVX-CoV2373; mRNA and adenoviral vector-based vaccines were also included as a reference. RESULTS: In total, 61 ICSRs included NVX-CoV2373. Most of the reports originated in Australia (50; 82.0%); 24 (39.3%) were considered serious. None of them were fatal. The median age of individuals was 35.5 years old, and most were males (38; 62.3%). Chest pain was the most common co-reported event 43 (70.5%). The median induction period was 3 days after immunization. Increased disproportionality for myopericarditis was found for NVX-CoV2373 (ROR 14.47, 95% confidence interval [CI] 11.22–18.67) and mRNA vaccines: BNT162b2 (ROR 17.15, 95% CI 16.88–17.42) and mRNA-1273 (ROR 6.92, 95% CI 6.77–7.08). Higher values were found in males. The adenoviral vector-based vaccine Ad26.COV2.S showed slightly increased disproportionality (ROR 1.83, 95% CI 1.70–1.98), whereas no increased disproportionality was found for ChAdOx1. CONCLUSIONS: NVX-CoV2373 vaccine showed a similar increased disproportionality as mRNA vaccines. More evidence from controlled studies is necessary; however, a precautionary approach is warranted. Healthcare professionals should be aware of the potential occurrence of myopericarditis with this new vaccine. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s40801-023-00355-5.