COVID-19 vaccination and myocarditis: A review of current literature

Abstract

Vaccination for coronavirus disease 2019 (COVID-19) is a critical strategy in controlling the current pandemic of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). After widespread COVID-19 vaccine imple-mentation, isolated case reports about myocarditis as a potential adverse reaction started coming. As of November 12, 2021, Centers for Disease Control and Prevention (CDC) has reported 1793 cases of myocarditis or pericarditis among young people with age 12-29 years, most cases have been reported in the male adolescent age group after the second dose of mRNA COVID-19 vaccines. It is very important to monitor the safety standards and adverse reactions of vaccines to effectively implement the vaccination policies. The CDC and the United States Food and Drug Administration actively monitor vaccine-associated adverse reactions a well-known platform such as Vaccine Adverse Event Reporting System. CDC continues to recommend COVID-19 vaccines and booster doses for eligible individuals (age limit according to the type of vaccine) after careful consideration from risk-benefit assessment and favorable outcomes from vaccination. Mechanisms behind COVID-19 vaccine-induced myocarditis are not clear yet but several possibilities such as molecular mimicry between the spike protein of SARS-CoV-2 and self-antigens, immune response to mRNA, and activation of host immunological system, trigger of the pre-existing dysregulated immunological system have been documented in the literature. Overall, data suggests a good prognosis, especially in young patients. In this review article, we cover currently available data on COVID-19 vaccine-related myocarditis incidence, concerns, possible mechanisms of myocarditis, current treatment, and outcome trends, risk vs benefit assessment of COVID-19 vaccination in this current pandemic.

Keywords: Coronavirus disease 2019 vaccine; Myocarditis; mRNA vaccine; Severe acute respiratory syndrome coronavirus-2; Vaccine complications; Risk assessment

Core Tip: Coronavirus disease 2019 (COVID-19) vaccination campaign is progressing successfully, and more than 400 million vaccine doses have been administered in the United States. We support the COVID-19 vaccination drive given positive data on preventing significant morbidities from COVID-19 disease in fully vaccinated people and relatively rare occurrences of serious side effects. Many questions remain open such as: whether patients with a history of vaccine-associated myocarditis should receive the subsequent vaccines or booster doses, the long-term effect of vaccine-associated myocarditis, how to identify the high-risk individuals for such adverse reactions to selectively save vulnerable populations, etc. There is still substantial research to be done in this direction to answer unsolved questions.