Association of Myocarditis With BNT162b2 Messenger RNA COVID-19 Vaccine in a Case Series of Children

Abstract

IMPORTANCEThe BNT162b2 (Pfizer-BioNTech) messenger RNA COVID-19 vaccine was authorized on May 10, 2021, for emergency use in children aged 12 years and older. Initial reports showed that the vaccine was well tolerated without serious adverse events; however, cases of myocarditis have been reported since approval.OBJECTIVE To review results of comprehensive cardiac imaging in children with myocarditis after COVID-19 vaccine. DESIGN, SETTING, AND PARTICIPANTSThis study was a case series of children younger than 19 years hospitalized with myocarditis within 30 days of BNT162b2 messenger RNA COVID-19 vaccine. The setting was a single-center pediatric referral facility, and admissions occurred between May 1 and July 15, 2021. MAIN OUTCOMES AND MEASURESAll patients underwent cardiac evaluation including an electrocardiogram, echocardiogram, and cardiac magnetic resonance imaging.RESULTS Fifteen patients (14 male patients [93%]; median age, 15 years [range, 12-18 years]) were hospitalized for management of myocarditis after receiving the BNT162b2 (Pfizer) vaccine. Symptoms started 1 to 6 days after receipt of the vaccine and included chest pain in 15 patients (100%), fever in 10 patients (67%), myalgia in 8 patients (53%), and headache in 6 patients (40%). Troponin levels were elevated in all patients at admission (median, 0.25 ng/mL [range, 0.08-3.15 ng/mL]) and peaked 0.1 to 2.3 days after admission. By echocardiographic examination, decreased left ventricular (LV) ejection fraction (EF) was present in 3 patients (20%), and abnormal global longitudinal or circumferential strain was present in 5 patients (33%). No patient had a pericardial effusion. Cardiac magnetic resonance imaging findings were consistent with myocarditis in 13 patients (87%) including late gadolinium enhancement in 12 patients (80%), regional hyperintensity on T2-weighted imaging in 2 patients (13%), elevated extracellular volume fraction in 3 patients (20%), and elevated LV global native T1 in 2 patients (20%). No patient required intensive care unit admission, and median hospital length of stay was 2 days (range 1-5). At follow-up 1 to 13 days after hospital discharge, 11 patients (73%) had resolution of symptoms. One patient (7%) had persistent borderline low LV systolic function on echocardiogram (EF 54%). Troponin levels remained mildly elevated in 3 patients (20%). One patient (7%) had nonsustained ventricular tachycardia on ambulatory monitor. CONCLUSIONS AND RELEVANCEIn this small case series study, myocarditis was diagnosed in children after COVID-19 vaccination, most commonly in boys after the second dose. In this case series, in short-term follow-up, patients were mildly affected. The long-term risks associated with postvaccination myocarditis remain unknown. Larger studies with longer follow-up are needed to inform recommendations for COVID-19 vaccination in this population.

Side Effects of COVID-19 Pfizer-BioNTech mRNA Vaccine in Children Aged 12–18 Years in Saudi Arabia

“…Given the rapid development and emergency authorization of COVID-19 vaccines, more trepidation about receiving COVID-19 vaccines were noticed among some populations worldwide. Furthermore, the recent reports of some rare cases of serious side effects such as thrombosis [33] and myocarditis [34,35] following COVID-19 vaccines may affect the acceptance of COVID-19 vaccines among some populations. Therefore, continuous monitoring of COVID-19 vaccines is essential to enhance the reassurance and acceptance of COVID-19 vaccines among the public.…”

“…The medium and long-term effects of the vaccine are still unknown in our study cohort. It would be of importance for future study to assess other rare events following COVID-19 vaccination such as thromboembolic profiles and myocarditis [34].…”

Systematic review of cardiac adverse effects in children and young people under 18 years of age after SARS-CoV-2 vaccination

“…Where reported, the median hospitalisation days ranged between 2 29 37 41 and 7 31 days, and all made full clinical recovery 28 30-37 39 42 43 except 14 patients 29 33 42 In the latter cases, at the time of discharge, three patients had mildly elevated troponin levels, one had persistent borderline low left ventricular systolic function on echocardiogram (EF 54%) and another had non-sustained ventricular tachycardia. 29 Three patients had abnormal cardiovascular magnetic resonance (CMR) results with late gadolinium enhancement (LGE). 29 Six patients' ECGs, at follow-up, revealed persistent changes, either nonspecific T-wave changes 33 29 , T-wave inversion 29 or a repolarisation abnormality.…”

Pediatrician’s role in vaccinating children and families for COVID-19: no one left behind

“…The rate of myocarditis after SARS-CoV-2 infection is estimated to be 6-34 times greater than the risk of messenger RNA vaccine-associated myocarditis and vaccine experts largely agree that the benefits of vaccination far outweigh the risk of myocarditis in children age 12 years and above. 21,22 Similar risk-benefit analyses should be conducted on children who are younger than 12 years of age and maybe at lower risk of severe COVID-19 infection.…”