Myocarditis following Coronavirus vaccination

Myocarditis is an adverse reaction discovered after the marketing of SARS-CoV-2 mRNA vaccines. Nevertheless, this effect is not mentioned as an adverse reaction in the summary of product characteristics of other types of vaccines against this disease.

In this work, we aim to present the cases of myocarditis after vaccination against COVID-19 reported to the national Tunisian centre of pharmacovigilance.

We present the cases of myocarditis reported after the COVID-19 vaccination. All cases are diagnosed according to Brighton's case definition of myocarditis. The vaccines causality assessment was estimated by the French imputability updated method of Bégaud et al.

We included five patients. The sex ratio (M/F) was 4. The mean age was 30 years. All patients had no notable cardiovascular history and did not report any significant past medical history. The onset of symptoms was two days post-vaccination in three patients. The predominant reported symptoms are chest pain and dyspnea in the five cases. Cardiac magnetic resonance imaging (MRI) confirmed the myocarditis diagnosis in four patients (not performed for one patient).All cases were classified as definitive cases according to the Brighton case definition of myocarditis. No patient required hospitalization in a cardiac intensive care unit. All the patients recovered from acute myocarditis within a few days.

Reported cases of myocarditis post-COVID-19 vaccination in our population are rare, not severe, and have a quick favorable outcome.