Myocarditis in SARS-CoV-2 infection vs. COVID-19 vaccination: A systematic review and meta-analysis

Abstract

BackgroundThis study aimed to compare the incidence of myocarditis in COVID-19 vaccines and in severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) infection groups.MethodsElectronic databases (MEDLINE, Scopus, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and the WHO Global Literature on Coronavirus Disease) and trial registries were searched up to May 2022, for randomized controlled trials and observational cohort studies reporting the risk of myocarditis associated with the COVID-19 vaccines and the risk associated with SARS-CoV-2 infection. We estimated the effect of COVID-19 infection and vaccines on rates of myocarditis by random-effects meta-analyses using the generic inverse variance method. Meta-regression analyses were conducted to assess the effect of sex and age on the incidence of myocarditis.ResultsWe identified 22 eligible studies consisting of 55.5 million vaccinated cohorts and 2.5 million in the infection cohort. The median age was 49 years (interquartile range (IQR): 38–56), and 49% (IQR: 43 to 52%) were men. Of patients diagnosed with myocarditis (in both vaccination and COVID-19 cohort) 1.07% were hospitalized and 0.015% died. The relative risk (RR) for myocarditis was more than seven times higher in the infection group than in the vaccination group [RR: 15 (95% CI: 11.09–19.81, infection group] and RR: 2 (95% CI: 1.44-2.65, vaccine group). Of patients who developed myocarditis after receiving the vaccine or having the infection, 61% (IQR: 39–87%) were men. Meta-regression analysis indicated that men and younger populations had a higher risk of myocarditis. A slow decline in the rates of myocarditis was observed as a function of time from vaccination. The risk of bias was low.ConclusionIn this systematic review and meta-analysis, we found that the risk of myocarditis is more than seven fold higher in persons who were infected with the SARS-CoV-2 than in those who received the vaccine. These findings support the continued use of mRNA COVID-19 vaccines among all eligible persons per CDC and WHO recommendations.

Comparison of COVID-19 Vaccine-Associated Myocarditis and Viral Myocarditis Pathology

“…A large meta-analysis compared the risk for myocarditis across approximately 58 million patients (55.5 million COVID-19 vaccinated patients and 2.5 million COVID-19 infection patients) across 22 studies, ten of which were specific to determining the risk of myocarditis in COVID-19 infected patients. This analysis found that the relative risk of myocarditis in COVID-19 infection was 14.82 [ 68 ]. Using the data presented in this analysis, 134,785 out of 2.4 million patients diagnosed with COVID-19 also met the qualifications for myocarditis [ 68 ].…”

“…This analysis found that the relative risk of myocarditis in COVID-19 infection was 14.82 [ 68 ]. Using the data presented in this analysis, 134,785 out of 2.4 million patients diagnosed with COVID-19 also met the qualifications for myocarditis [ 68 ]. A Centers for Disease Control (CDC) Morbidity and Mortality report also found a relative risk of 15.7 for the development of COVID-19 infection-associated myocarditis compared to non-COVID-19 patients [ 69 ].…”

Myocarditis and Pericarditis Following the SARS-CoV-2 Infection and COVID-19 Vaccination

“…Moreover, these vaccine-induced AEs have been reported following mRNA (Moderna or Pfizer/BioNTech) and adenoviral vector (Johnson & Johnson) vaccines [55,[60][61][62]. Although the risk of developing myocarditis following COVID-19 vaccination is much lower than infection to SARS-Cov-2, the risk of vaccineinduced myocarditis increases following sequential administration of further vaccine doses [7,63]. Nonetheless, the Centers for Disease Control and Prevention (CDC) guidelines still indicate safety assurance for receiving these COVID-19 vaccines based on benefit-risk assessment in adolescents and young adults.…”

Long Covid: Untangling the Complex Syndrome and the Search for Therapeutics

“…Specific long-lasting inflammatory reactivity due to organ damage, central nervous system complications, gastrointestinal (GI) distress, auto-immunity, endothelial dysfunction, and coagulation dysregulation all have been implicated in the development of Long Covid pathogenesis ( Figure 2 ). Studies indicate that myocarditis is seven times more likely to occur in patients with COVID-19 infection vs. patients who have been vaccinated [ 21 ].…”