Two Cases of Acute Myocarditis in Young Male Adults After mRNA Vaccines Against COVID-19: Similarities and Differences

BACKGROUND: The advent of the new coronavirus SARS-CoV-2 has created unprecedented situations, both in terms of health and socio-economic level, worldwide. The emergence of vaccines against this highly contagious virus has raised hopes for its effective inhibition. The efficacy of vaccines, in more than a year of their application in clinical practice, is indisputable, both in terms of reducing serious hospitalizations and deaths, especially in high-risk populations. As with any new medication, the quest and investigation for side effects are reasonable. Myocarditis is one of the extremely rare side effects reported in mRNA vaccines, especially in young males. CASE PRESENTATION: We present two cases of myocarditis that occurred in our hospital in a short time between them and compare them point by point to identify similarities and differences in order to draw conclusions about the severity of this side effect and its outcome. CONCLUSION: The benefits of vaccination against Covid-19 outweigh possible untoward effects and especially myocarditis. Health workers must close monitor the vaccinated patients for possible future cardiovascular complications.