Safety of BNT162b2 COVID-19 Vaccine in Adolescents

Quick Takes

  • The BNT162b2 vaccine appears safe and effective in patients ages 12-15 years.
  • The BNT162b2 vaccine elicits a stronger immune response than that seen in patients ages 16-25 years.

Study Questions:

What is the safety, immunogenicity, and efficacy of the BNT162b2 coronavirus disease 2019 (COVID-19) vaccine in adolescents?


A multinational, placebo-controlled, observer-blinded trial was performed. Participants were randomly assigned in a 1:1 ratio to receive two injections 21 days apart of 30 µg of BNT162b2 or placebo. The primary immunogenicity objective was noninferiority of the immune response in 12- to 15-year-old participants as compared with that in 16- to 25-year-old participants. Safety and efficacy against confirmed COVID-19 onset ≥7 days after the second dose in the 12- to 15-year-old cohort were assessed.


A total of 2,260 adolescents 12-15 years of age received injections, of which 1,131 received vaccine and 1,129 received placebo. The most common side effects included injection-site pain in 79-86% of participants, fatigue in 60-66%, and headache in 55-65%. There were no vaccine-related serious adverse events. The geometric mean ratio of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) 50% neutralizing titers after dose 2 in 12- to 15-year-olds relative to 16- to 25-year-olds was 1.76 (95% confidence interval [CI], 1.47-2.1), and indicated a greater response in the 12- to 15-year-old cohort. Among patients without evidence of previous SARS-CoV-2 infection, no COVID-19 cases occurred ≥7 days after dose 2 in vaccine recipients as compared with 16 cases among placebo recipients for a vaccine efficacy of 100% (95% CI, 75.3-100).


The authors concluded that the BNT162b2 vaccine in 12- to 15-year-old recipients had a favorable safety profile, produced a greater immune response than in young adults, and was highly effective against COVID-19.


This study demonstrated safety and efficacy of the BNT162b2 vaccine in patients ages 12-15 years. The vaccine demonstrated 100% efficacy in this cohort, with higher levels of immunogenicity than that seen in older patients. One limitation of the study is the relatively small sample size such that relatively rare side effects may be seen only when the vaccine is administered on a larger scale. Along these lines, there have been anecdotal reports of myocarditis after vaccine administration, particularly in young males after the second dose. Early reports from Israel have suggested that myocarditis is not occurring at a higher than expected frequency based on historical data. Cases reported thus far appear to be mild and self-limited. Current guidance from the Centers for Disease Control and Prevention (as of 5/28/2021) continues to recommend vaccination for all patients greater than age 12. Myocarditis appears to be quite rare given the number of patients vaccinated thus far, although further study of this issue will be necessary moving forward.

Clinical Topics: Congenital Heart Disease and Pediatric Cardiology, Heart Failure and Cardiomyopathies, Prevention, CHD and Pediatrics and Arrhythmias

Keywords: ACC COVID-19 Podcast, Adolescent, Coronavirus, COVID-19, Fatigue, Headache, Immunity, Myocarditis, Pain, Pediatrics, Primary Prevention, SARS-CoV-2, Vaccination, Young Adult

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