Serum Troponin I Assessments in 5-to 30-Year-Olds After BNT162b2 Vaccination

Abstract

Introduction: Rare myocarditis and pericarditis cases have occurred in coronavirus disease 2019 (COVID-19) messenger RNA (mRNA) vaccine recipients. Troponin levels, a potential marker of myocardial injury, were assessed in healthy participants before and after BNT162b2 vaccination. Methods: Vaccine-experienced 12-to 30-year-olds in phase 3 crossover C4591031 Substudy B (NCT04955626) who had two or three prior BNT162b2 30-lg doses were randomized to receive BNT162b2 30 lg followed by placebo, or placebo followed by BNT162b2 30 lg, 1 month apart. A participant subset, previously unvacci-nated against COVID-19, in the phase 3 C4591007 study (NCT04816643) received up to three vaccinations (BNT162b2 10 lg or placebo [5-to 11-year-olds]) or open-label BNT162b2 30 lg (12-to 15-year-olds). Blood samples collected pre-vaccination, 4 days post-vaccination, and 1-month post-vaccination (C4591031 Sub-study B only) were analyzed. Frequencies of elevated troponin I levels (male, > 35 ng/l; female, > 17 ng/l) were assessed. Results: Percentages of 12-to 30-year-olds (n = 1485) in C4591031 Substudy B with elevated troponin levels following BNT162b2 or placebo receipt were 0.5% and 0.8% before vaccination, 0.7% and 1.0% at day 4, and 0.7% and 0.5% at 1 month, respectively. In Study C4591007 (n = 1265), elevated troponin I levels were observed in 0.2, 0.4, and 0.2% of 5-to 11-year-old BNT162b2 recipients at baseline and 4 days post-dose 2 and 3, respectively; cor-responding values in 12-to 15-year-olds were 0.4, 0.4, and 0.7%. No 5-to 11-year-old placebo recipients had elevated troponin levels. No myocarditis or pericarditis cases or deaths were reported. Conclusions: Among 5-to < 30-year-olds in both studies, troponin levels were rarely elevated (≥ 1.0%) and similar before and post-vaccination; troponin levels were also similar between BNT162b2 and placebo in 12-to 30-year-old and 5-to 11-year-old recipients in the respective studies. No myocarditis or peri-carditis cases were reported. These findings did not provide evidence that BNT162b2 causes troponin elevations. No utility of routine mea-surement of troponin levels in asymptomatic BNT162b2 recipients was identified.