COVID-19 Evidence Alerts
from McMaster PLUSTM

Current best evidence for clinical care (more info)

Etiology Li M, Wang X, Feng J, et al. Myocarditis or Pericarditis Following the COVID-19 Vaccination in Adolescents: A Systematic Review. Vaccines (Basel). 2022 Aug 15;10(8):1316. doi: 10.3390/vaccines10081316.
PICO Terms
adolescent (P) adverse reactions; safety (O) children (P) Comirnaty; Pfizer vaccine; BNT162b2; BioNTech/Fosun Pharma; mRNA (I/C) fully vaccinated (I/C) partially vaccinated (I/C) pediatric (P)

Background: By 16 May 2022, 12,186,798,032 people had been vaccinated with COVID-19 vaccines. Our study found that myocarditis/pericarditis may occur in adolescents after COVID-19 vaccination. Methods: In this regard, we conducted a meta-analysis of seven groups of adolescents aged 12-19 years to compare the incidence of myocarditis/pericarditis after vaccination and compare the relative risk incidence after the first and second doses of a COVID-19 vaccine, and between males and females for risk incidence. Results: We analyzed 22,020,997 subjects from seven studies, including 130 cases of confirmed myocarditis/pericarditis. The overall mean incidence rate was 1.69 cases per 100,000 person-years. Of these, 19 of the 12,122,244 people who received a first dose of a COVID-19 vaccine had myocarditis/pericarditis, an incidence rate of 0.0022% (95% CI 0.0001-0.0034), and 111 of the 1,008,753 people who received a second dose had myocarditis/pericarditis, an incidence rate of 0.0107% (95% CI 0.0059-0.0155). The prevalence relative ratio (RR) after the first and second doses was RR = 5.53 (95% CI: 3.01-10.16), with a higher prevalence after the second dose than after the first dose of a COVID-19 vaccine. After a second dose of a COVID-19 vaccine, the RR for males relative to females was RR = 13.91 (95% CI: 4.30-44.95), with a more pronounced risk of disease in males than in females. Conclusions: Our study showed that myocarditis/pericarditis occurred after vaccination with the BNT162b2 or Comirnaty vaccine, especially after the second vaccination in male adolescents, but the incidence of myocarditis/pericarditis after vaccination with the above vaccines was very rare (0.0022%). Therefore, it is recommended that adolescents should be vaccinated with the COVID-19 universal vaccine as soon as possible and closely monitored for subsequent adverse reactions, which can be treated promptly.

Discipline / Specialty Area Score
Infectious Disease
Pediatrics (General)
Family Medicine (FM)/General Practice (GP)
Public Health
Internal Medicine
Comments from MORE raters

Cardiology rater

Very clinically relevant information in a large population of participants.

Family Medicine (FM)/General Practice (GP) rater

As far as I can see, baseline risk for myocarditis and COVID-related risk for myocarditis were not considered, so this study does not provide indications of the additional risk related to vaccination in itself.

Infectious Disease rater

Very important information for pediatricians dealing with hesitant parents about immunizing their children. However, data from randomized clinical trials should have been included in the metanalysis.

Pediatrics (General) rater

With the Covid-19 vaccines being rolled out to younger age groups, the incidence of pericarditis/myocarditis needs to be anticipated. This study provides useful data, that despite a small relative risk, the history of vaccination must be identified if adolescents present with unexplained myocarditis/pericarditis.