Case Report: Two Case Reports of Acute Myopericarditis After mRNA COVID-19 Vaccine

Abstract

Background: Cases of myocarditis and myopericarditis after mRNA COVID-19 vaccines have been reported, especially after the second dose and in young males. Their course is generally benign, with symptoms onset after 24-72 h from the dose.

Case summary: We report two cases of myopericarditis after the second dose of the mRNA-1273 COVID-19 vaccine in two young males. Both the patients were administered the mRNA-1273 COVID-19 vaccine from the same batch on the same day and experienced fever on the same day of the vaccine, and symptoms consisted of myopericarditis 3 days after the dose.

Discussion: Myopericarditis is usually considered an uncommon adverse reaction after various vaccinations, reported also after the mRNA COVID-19 vaccine. Several explanations have been proposed, including an abnormal activation of the immune system leading to a pro-inflammatory cascade responsible for myocarditis development. Both patients experienced the same temporal onset as well as the same symptoms, it is also useful to underscore that both vaccines belonged to the same batch of vaccines. However, despite these cases, vaccination against COVID-19 far outweighs the risk linked to COVID-19 infection and remains the best option to overcome this disease.

Keywords: COVID-19; case report; mRNA vaccine; myocarditis; myopericarditis.

Figure 1

Twelve-lead resting electrocardiograms collected at the hospital admission. Patients' electrocardiograms on admission: 20-year-old patient (A) and 21-year-old patient (B). The resting ECGs showed sinus rhythm, normal atrioventricular conduction, incomplete right bundle branch block and no ventricular repolarization abnormalities.

Figure 2

(A,B) Central illustration. The picture summarizes the main non-invasive findings in the two patients experiencing acute myopericarditis after mRNA-1273 COVID-19 vaccine. See text for details.

Figure 3

T-wave inversion showed by twelve-lead resting electrocardiograms. Patients' electrocardiograms on day 2 from admission show T-wave inversion in the anterolateral leads in the 20-years old patient (A), whereas in the other patient, the T-wave inversion occurred in the lateral leads (B).

Figure 4

Timeline. Timeline of the two patients from the day of the vaccine and symptoms onset to discharge.

Figure 5

Resting electrocardiograms after hospital discharge. Patients' electrocardiograms after one month from hospital discharge show almost complete resolution of repolarization abnormalities in both patients [in the 20-years old patient (A) and in the 21-year old patient (B)].