This evidence review was compiled by members of the CITF Secretariat with the input from experts affiliated with the CITF and does not necessarily reflect the views of all CITF members.

By Alexis Palmer-Fluevog

In their recent publication in The New England Journal of Medicine, researchers Dr. Kashir Ali, Dr. Gary Berman and colleagues presented the interim results of the Moderna vaccine trial in adolescents aged 12 to 17. The authors highlighted the safety of the vaccine and the 93% efficacy shown in this phase 2-3 trial. If granted approval, this vaccine will be the second vaccine available to help combat COVID-19 among adolescents.

Key points:

  • No serious adverse effects were reported among participants; however, participants did report non-serious adverse events such as injection-site pain, headache, and fatigue following injection.
  • Side effects lasted for about 4 days on average.
  • The immune response among adolescents was similar to that of young adults aged 18-25.
  • Vaccine efficacy against a COVID infection was 93% by 14 days after the second injection.
  • Based on the findings, the authors suggest the overall benefit–risk of the Moderna vaccine to be favorable in adolescents.

A total of 3,732 healthy 12- to 17-year-olds participated in the trial, receiving two doses of the vaccine 28 days apart. The data from this study suggest that the Moderna vaccine has an acceptable safety profile and is effective in preventing COVID-19 infection. As adolescents get ready to head back to classes in the fall, this vaccine can be another additional tool to help ensure that the school year is a safe one.


Ali K, Berman G, Zhou H, Deng W, Faughnan V, Coronado-Voges M, Ding B, Dooley J, Girard B, Hillebrand W, Pajon R, Miller JM, Leav B, Mcphee R, 2021. Evaluation of mRNA-1273 SARS-CoV-2 Vaccine in Adolescents. New Engl J Med. 11 Aug 2021. doi:10.1056/nejmoa2109522