This evidence synthesis has been compiled by members of the CITF Secretariat and does not necessarily represent the views of all CITF members.

By Mariana Bego

Pfizer-BioNTech and Moderna are reporting that their mRNA COVID-19 vaccines appear to be safe and efficacious in 12- to 16-year-olds, consistent with results reported for adults. Safety and effectiveness results of the Pfizer vaccine for this demographic were recently published in New England Journal of Medicine. Moderna announced their preliminary data in a press release.

Key points:

  • Both Pfizer-BioNTech and the Moderna mRNA report that their mRNA vaccines appear to be safe and effective against COVID-19 in children aged 12-16
  • Children (aged 12-15) produced a greater immune response when compared to young adults (aged 16-25) after two doses of the Pfizer vaccine

Results from ongoing phase three trials involving nearly 2,300 US adolescents between the ages of 12 and 16 point to a high level of effectiveness with the Pfizer vaccine after two doses.1 No COVID-19 infections were reported in the vaccinated group (0/1131) compared to 16 cases of infection in the unvaccinated control group (16/1129, or 1.42%). Two months after the vaccine was given, adverse events were rare and generally mild. Interestingly, the levels of neutralizing antibodiesAntibodies that bind to the surface structures of a pathogen, preventing it from entering and infecting its host cells. were significantly greater in those aged 12-15 compared to those in the 16-25 age range.

Moderna also announced that their COVID-19 vaccine appears to be safe and effective for teenagers.2 Their TeenCOVE study enrolled more than 3,700 US participants between the ages of 12 and 18. No cases of COVID-19 were observed in participants who had received two doses, compared to four cases in the placebo group. The company also reported that no significant safety concerns have been identified to date. On Monday, June 7, 2021, Moderna said it had filed for Health Canada authorization for its COVID-19 vaccine to be used in adolescents.3

Several research reports have indicated that adolescents play an important role in SARS-CoV-2 transmission and experts believe that they are needed to reach herd immunity. Vaccinating this age group also carries the secondary benefit of reducing the risk of household and in-school transmission. In addition, the pandemic has interrupted the social development and overall wellbeing of teens, while also placing significant burden on parents (Read more on Dr. Zinszer’s study).



  1. Frenck RW, Klein NP, Kitchin N, Gurtman A, Absalon J, Lockhart S,  Perez JL, Walter EB, Senders S, Bailey R, Swanson KA, Ma H, Xu X, Koury K, Kalina WV, Cooper D, Jennings T, Brandon DM, Thomas SJ, Tresnan DB, Mather S, Dormitzer PR, Şahin U, Jansen KU, Griber WC, for the C4591001 Clinical Trial Group. Safety, Immunogenicity, and Efficacy of the BNT162b2 Covid-19 Vaccine in Adolescents. N Engl J Med. 2021 May 27. doi: 10.1056/NEJMoa2107456.
  2. Moderna Announces TeenCOVE Study of its COVID-19 Vaccine in Adolescents Meets Primary Endpoint and Plans to Submit Data to Regulators in Early June. Press release May 25th 2021.
  3. Coronavirus: Moderna files for Canadian authorization to give teens its COVID-19 vaccine | CTV News