Rare complications

Changes of ECG parameters after BNT162b2 vaccine in the senior high school students

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Data collected, December 2021

Published, January 2023

Aims

Determine the ECG parameter change

Determine efficacy of ECG screening after the second dose of BNT162b2

In cooperation with the school vaccination system of Taipei City government (Taiwan)

N = 4,928 (mostly male)

12 to 18 year old

Before and after 12 lead ECGs

Three follow up 12 lead ECGs

ECGs read by by pediatric cardiologists

Serial comparisons of ECGs and questionnaire survey

Heart rate increased significantly after the vaccine,

(mean increase of 2.6 beats per minute)

QRS duration and QT interval decreased significantly after the vaccine with increasing heart rate

763 (17.1%) had at least one cardiac symptom after the second vaccine dose.

After the first dose, 209 (5.7%) had at least one cardiac symptom

Cardiac symptoms

Chest pain

Palpitations

Dizziness or syncope

Depolarization and repolarization parameters

All 4 cardiac symptoms significantly higher after the second dose of BNT162b2 vaccine (p less than 0.001)

N = 4,928

Abnormal ECGs were obtained in 51 (1.0%)

31 students were asymptomatic

ST – T changes, 37

Premature ventricular contractions, 4

Sinus bradycardia, 2

Atrial tachycardia, 1

Incomplete right bundle branch block, 3

Abnormal QRS, 2

Prolonged QT, 2

4 judged to have significant arrhythmia

1 was diagnosed with mild myocarditis

10, suspected pericarditis

All of these symptoms improved over time

Asymptomatic at one month

No covid in Taiwan at this time.

Conclusion

Cardiac symptoms are common after the second dose of BNT162b2 vaccine

Incidences of significant arrhythmias and myocarditis are 0.1%

One in a thousand

Rotavirus vaccine Rotashield, (1999)

1 to 2 serious events per 10,000 vaccinees

(Intussusception)

Vaccine withdrawn

From the authors

BNT162b2 has a better safety profile than mRNA-1273 Moderna

Cardiac-related adverse effects, as peri- and myocarditis, are of particular concern because of possible serious complications

US vaccina advice

CDC recommends one updated (bivalent) booster dose:

• For everyone aged 5 years and older if it has been at least 2 months since your last dose.

• For children aged 6 months–4 years who completed the Moderna primary series and if it has been at least 2 months since their last dose.

UK vaccine advice

Who can get a COVID-19 vaccine

Everyone aged 5 (on or before 31 August 2022) and over can get a 1st and 2nd dose of the COVID-19 vaccine.

People aged 16 and over, and some children aged 12 to 15, can also get a booster dose.