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.