Cardiac adverse events post-vaccination

Some vaccine recipients experience cardiac adverse events (AEs) following immunization (AEFIs), which include background events and vaccine-associated AEs for certain vaccines. A small subset of AEs experienced by vaccine recipients is documented in the United States Vaccine AE Reporting System (VAERS). This study retrospectively analyzed VAERS to identify associations for cardiac AEFIs. The analysis considered factors such as vaccine type, vaccine source, vaccine recipient gender, and infant age. Multiple patterns of cardiac AEFI associations were detected: (i) bradycardia and cardiac arrest for infants under 1 year of age, (ii) arrhythmia for COVID-19 and human papillomavirus vaccines, (iii) atrial fibrillation for COVID-19, influenza, and respiratory syncytial virus vaccines, (iv) myocarditis and pericarditis for anthrax, COVID-19, smallpox, and typhoid vaccines, and (v) chest discomfort, chest pain, palpitations, and tachycardia for multiple vaccines. Gender differences were observed for both myocarditis and palpitation AEFIs. Significant differences in bradycardia and cardiac arrest AEFI normalized frequencies were observed for the same infant vaccines from different manufacturers, suggesting possible manufacturing contaminants as potential causative components. In conclusion, delaying specific vaccines until infants are 1 year old, selecting alternative vaccine options, or reducing or eliminating causative components could reduce infant bradycardia and cardiac arrest AEFIs. Mathematical age relationships could model both male and female myocarditis AEs for COVID-19 vaccines, potentially applicable to other vaccines, suggesting shared etiologies. In addition, several vaccines were associated with correlated cardiac AEFI signals for chest discomfort, chest pain, palpitations, and tachycardia. The etiologies of these AEFIs could be attributed to elevated histamine levels.