RESUMEN
Although extremely rare, the COVID-19 mRNA vaccine can induce myopericarditis without left ventricular dysfunction, and there have been rare reports of such incidents. However, these prior cases either did not have pericardial effusion without reduced left ventricular ejection fraction or had a more typical presentation of vaccine-induced myopericarditis such as shortness of breath or tactile temperature. We present a rare case of a 25-year-old man who developed myopericarditis following administration of the second dose of COVID-19 mRNA Vaccine. As vaccination plays a significant role in the fight against the COVID-19 pandemic, it is essential to highlight the physical manifestations of the vaccine's potential adverse effects and risk factors to increase the general population's awareness regarding the importance of emergent medical care.