Link to study abstract.
Link to full pdf of in press study: Asymp Myocardial Injury after BNT162b2 mRNA COVID-19 Fourth dose
“…two participants out of 324 (0.6%) were found to have an acute myocardial injury in the days following vaccine administration. Both participants had no evidence of clinical myocarditis and had normal electrocardiogram and echocardiography, with a normal CMR in the symptomatic participant…Although considered to be low, the estimated risk of myocarditis and myocardial injury in vaccine recipients is believed to be underestimated. Indeed, the current study suggests a higher incidence of myocardial injury during active monitoring for cardiac biomarkers in vaccine recipients with no clinical evidence of myocarditis. Since in our study the average age was 51 and only 40% were males with only 8 (2.47%) of them that were 30 years old or younger, it is currently unknown if a prospective evaluation among younger males will yield a higher incidence of myocardial injury.”
“…the clinical significance of the mild injury found in our study may be debated and should be further evaluated in larger studies. A reasonable recommendation may be to withhold strenuous physical activity for a few months. Regarding the recommendation for repeat vaccine doses in the future, there is no consensus.
However, given the limited clinical utility reported recently with the fourth dose against Omicron, repeat vaccination of individuals with documented post-vaccine myocardial injury deserves a profound risk-benefit consideration.”
Study abstract, design figure, and key results figure and table, below: