Within 1 month of receipt of any COVID-19 vaccine, 11 individuals had documented symptoms suggesting cardiac involvement, specifically, chest pain, palpitations, or dyspnea. After cardiac evaluation, 4 patients met the criteria for VAMP after COVID-19 vaccination.10,11 Seven patients either did not meet the criteria for VAMP or had alternative causes for their symptoms.
Two men aged 49 and 50 years with a history of vaccine-associated myocarditis following smallpox vaccination (Dryvax and ACAM2000) developed myocarditis 3 days after their second dose of the Moderna vaccine. One of these patients received a Pfizer-BioNTech booster 10 months later with no recurrence of symptoms. A 55-year-old man with a history of vaccine-associated myocarditis following Dryvax vaccination developed myocarditis 2 days after his Pfizer-BioNTech booster. None of the patients who developed post-COVID-19 VAMP reported residual symptoms from their initial VAMP episode, which occurred 12 to 18 years earlier. All were hospitalized briefly for observation and had complete symptom resolution within 6 weeks.
A 25-year-old man developed pericarditis 4 days after his second Pfizer-BioNTech vaccination. His previous ACAM2000 vaccine-associated myocarditis occurred 3 years earlier, with no residual symptoms. Of note, he had a mild COVID-19 infection 78 days before the onset of his pericarditis. After the onset of his COVID-19 vaccine-associated pericarditis, he continued to experience transient bouts of chest pressure and exertional dyspnea that resolved within 7 months of onset.
The median interval between COVID-19 vaccine doses in those who developed post-COVID-19 VAMP was within the recommended mRNA vaccine dosing intervals of 3 to 4 weeks and was consistent with the median mRNA vaccine dosing intervals among the entire cohort.
Due to the small cohort size and other limitations of this study, the suggested rate of cardiac injury in this review (4 cases in 179 persons, or 2.2%) is an imprecise estimate of risk in a small population (95% CI, 0.1%-4.4%). While this rate may seem higher than expected within the general population after COVID-19 vaccination, it is lower than the estimated lifetime risk of recurrent myocarditis from any cause.6,12