Acute pericarditis following mRNA COVID-19 vaccination: An unforeseen event

In this article, we reported a case of mRNA COVID-19 vaccination-induced pericarditis. A healthy 32-year-old gentleman who had no medical illness presented with left-sided pleuritic chest pain with a pain score of 8/10, a few days after 2nd dose of mRNA COVID-19 vaccination. The symptom was associated with palpitation, radiating to the axilla, and improved with leaning forward. Despite normal cardiac enzymes, serial electrocardiograms were suggestive of pericarditis and echocardiogram showed features of pericardial thickening. Infective markers and autoimmune screening sent were not significant. The patient was treated with high-dose NSAIDs and colchicine and recovered well. A repeated echocardiogram after 1 week of treatment completion showed resolved pericardial thickening and normal findings. DISCUSSION: To date, rising cases have been reported on the incidence of pericarditis post mRNA COVID-19 vaccine. This raises suspicion on why this event only occurs after vaccine with the mRNA-based platform. Several hypotheses have been postulated. It has been suspected that mRNA vaccines possibly generate a very high signal antibody response in certain individuals, thus eliciting a response similar to that of Multisystem Inflammatory Syndrome in children (MIS-C) or mimicking an autoimmune-like response which targets pericardial lining. mRNA vaccines can induce a non-specific innate inflammatory response between the viral spike protein and an unknown cardiac protein. Another hypothesized mechanism, the RNA in the vaccine itself leads to cytokine activation of pre-existing autoreactive immune cells as young people usually have higher seroprevalence of SARS-COV-2 despite being asymptomatic. CONCLUSION: We wish to highlight the importance of monitoring and treating adverse events notable by patients. Healthcare providers should maintain high suspicion in the appropriate clinical situation. All cases were self-limited and showed satisfactory recovery during follow-up. We emphasize the benefit of vaccination outweighs the risk.