Cardiovascular Effects of the BNT162b2 mRNA COVID-19 Vaccine in Adolescents
Version 1 : Received: 7 August 2022 / Approved: 8 August 2022 / Online: 8 August 2022 (10:40:23 CEST)
A peer-reviewed article of this Preprint also exists.
Mansanguan, S.; Charunwatthana, P.; Piyaphanee, W.; Dechkhajorn, W.; Poolcharoen, A.; Mansanguan, C. Cardiovascular Manifestation of the BNT162b2 mRNA COVID-19 Vaccine in Adolescents. Trop. Med. Infect. Dis. 2022, 7, 196. Mansanguan, S.; Charunwatthana, P.; Piyaphanee, W.; Dechkhajorn, W.; Poolcharoen, A.; Mansanguan, C. Cardiovascular Manifestation of the BNT162b2 mRNA COVID-19 Vaccine in Adolescents. Trop. Med. Infect. Dis. 2022, 7, 196.
Journal reference: Trop. Med. Infect. Dis. 2022, 7, 196
This study focuses on cardiovascular effects, particularly myocarditis and pericarditis events, after BNT162b2 mRNA COVID-19 vaccine injection in Thai adolescents. This prospective cohort study enrolled students from two schools aged 13–18 years who received the second dose of the BNT162b2 mRNA COVID-19 vaccine. Data including demographics, symptoms, vital signs, ECG, echocardiography and cardiac enzymes were collected at baseline, Day 3, Day 7, and Day 14 (optional) using case record forms.We enrolled 314 participants; of these, 13 participants were lost to follow up, leaving 301 participants for analysis. The most common cardiovascular effects were tachycardia (7.64%), shortness of breath (6.64%), palpitation (4.32%), chest pain (4.32%), and hypertension (3.99%). Seven participants (2.33%) exhibited at least one elevated cardiac biomarker or positive lab assessments. Cardiovascular effects were found in 29.24% of patients, ranging from tachycardia, palpitation, and myopericarditis. Myopericarditis was confirmed in one patient after vaccination. Two patients had suspected pericarditis and four patients had suspected subclinical myocarditis. Conclusion: Cardiovascular effects in adolescents after BNT162b2 mRNA COVID-19 vaccination included tachycardia, palpitation, and myocarditis. The clinical presentation of myopericarditis after vaccination was usually mild, with all cases fully recovering within 14 days. Hence, adolescents receiving mRNA vaccines should be monitored for side effects. Clinical Trial Registration: NCT05288231
Fact Check-Study of Thai teenagers did not find one third experienced heart effects after COVID vaccination
A study of 301 teens in Thailand found mild and temporary heart rhythm changes after a second dose of the Pfizer-BioNTech COVID-19 vaccine among one in six teenagers, not one-third as social media posts claim. The study also saw possible signs of heart inflammation in just seven of those teens with rhythm changes and confirmed myocarditis in only one of the seven.
Social media users are circulating the study of post-vaccination heart effects in Thai teenagers with the claim that a third of participants experienced heart effects, and the suggestion that the results indicate a new danger level for children. These posts are missing context: the study’s authors concluded, “We found the risk of these symptoms to be not as low as reported elsewhere, but in all cases, symptoms were mild with full recovery within 14 days.”
A Twitter post shared more than 11,000 times (here) contains a link to the preprint study by Suyanee Mansanguan of Bhumibol Adulyadej Hospital in Bangkok and colleagues, with the comment, “BREAKING: A new study has found cardiovascular adverse effects in around a third of teens following Pfizer vaccination, and heart inflammation in one in 43, raising fresh concerns about the risks of vaccination for young people. This is beyond concerning.”
Mansanguan and colleagues note in their draft study, released as a preprint on Aug. 8 (here), that they likely saw higher rates of heart rhythm disturbance and signs of inflammation than in other studies because they did tests that detected mild changes in participants with no symptoms who would not ordinarily have been screened.
The analysis included 301 people aged 13-18 recruited from two Bangkok schools before receiving their second dose of the Pfizer-BioNTech mRNA COVID-19 vaccine in November and December of 2021. The students were mostly male (67%) and none had “abnormal” symptoms after their first vaccine shot, the study notes.
Before receiving the second vaccine shot, each participant had a physical exam, a heart ultrasound called an echocardiogram, heart rhythm measurements by electrocardiogram (ECG or EKG) and blood tests to look for heart-related biomarkers including Troponin-T and CK-MB, both markers of damage to heart muscle. The exam and the tests were repeated on days 3 and 7 following the second vaccine shot, and on day 14 for some of the teenagers. The participants also kept symptom diaries throughout the study period and were able to contact or visit the study team doctors at any time to ask questions or discuss unusual symptoms.
Overall, 50 of the 301 students reported fever after the second vaccine shot and 35 reported headache, both common general side effects following COVID-19 vaccination.
Among cardiovascular effects detected only by ECG, 54 participants (18%, so roughly one in six, not one in three as social media rates) had rapid heartrate or abnormal heart rhythm. Of these, 39 had reported symptoms such as palpitations or chest pain. Fifteen reported no symptoms at all.
Among the participants with abnormal ECG, seven – all males — also had elevated biomarkers of heart muscle injury or inflammation. Of these seven, four had reported chest discomfort or pain, but three had no symptoms other than the elevated biomarkers. All seven also had normal heart function and no sign of reduced pumping ability that can signal heart failure.
The Thai team confirmed one case of myocarditis (heart inflammation) in the 301 students — not one in 43 as suggested in social media posts.
False. The study of teenagers in Thailand following a second COVID-19 vaccination found that 18% — not one third — experienced any detectable cardiac effect, and that 1 in 301, not 1 in 43, had confirmed myocarditis. A large proportion of purported abnormalities detected by testing were without symptoms, and 100% of the teens in the study fully recovered after 14 days, the authors reported.
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