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COVID-19 Vaccine Trials in Kids: Where Do They Stand?

Child getting a vaccine shot in their arm.

Malte Mueller / Getty Images

Key Takeaways

  • Several clinical trials testing COVID-19 vaccines in kids are currently underway.
  • Children as young as 12 are now eligible to receive the Pfizer-BioNTech COVID-19 vaccine.

Now that over half of the U.S. adult population has received at least one dose of the COVID-19 vaccine, the country is expanding its efforts to get kids vaccinated next.

Currently, there are three COVID-19 vaccines authorized for use in the U.S., but clinical trials are still underway to determine if these vaccines are safe for younger age groups.

Kids under the age of 16 are now eligible for a COVID-19 vaccine in the United States. On Monday, May 10, the Food and Drug Administration (FDA) authorized the Pfizer-BioNTech vaccine for use in adolescents ages 12 through 15.

Seven U.S.-based clinical trials are testing the COVID-19 vaccines in children right now (an eighth is taking place in the U.S. and the U.K.), with some study participants as young as 6 months. But not every trial is at the same stage.

Here’s where clinical trials on COVID-19 vaccines in children in the U.S. stand, plus when you can expect them to release results.

What Are the Phases of a Clinical Trial?

The clinical development of a vaccine is a three-phase process, according to the Centers for Disease Control and Prevention (CDC):

  1. Phase 1: During a Phase 1 study, scientists try to determine the strongest vaccine dose that causes the fewest side effects. This helps determine the proper dose to administer to people. A few dozen people participate in Phase 1 studies. 
  2. Phase 2. In a Phase 2 study, the vaccine is tested among hundreds of people who have similar characteristics, such as age, gender, and medical conditions, to determine how effective the vaccine is in certain types of people. If Phase 2 studies are successful, people will produce antibodies, and the clinical trial moves into Phase 3.
  3. Phase 3. The purpose of Phase 3 clinical trials is to evaluate the safety of a vaccine. Thousands of people participate in Phase 3 trials and scientists continue to monitor the effectiveness of the vaccine, as well as side effects that people experience.  

Pfizer

Trial NCT04368728

  • Ages included: 12 and older
  • Number of people (all ages): 43,998
  • Clinical trial phase: Phase 2/3
  • What the trial is looking at: The trial is looking to determine the safety and tolerability of this vaccine. Researchers are also analyzing the vaccine's ability to trigger an immune response and how well it works at preventing COVID-19. The trial will also examine the efficacy of the vaccine as a booster, but only in adults age 18 years and older.
  • Kid-specific results: Pfizer announced in a press release in late March that its vaccine was 100% effective at protecting children ages 12 to 15 against COVID-19 and created “robust antibody responses, exceeding those recorded earlier in vaccinated participants aged 16 to 25 years old.” It was also “well-tolerated."
  • Timeframe: April 29, 2020 – May 2, 2023 (May refers to the primary completion date, meaning the date on which the last participant was examined or received an intervention to collect final data for the primary outcome measure: vaccine safety/side effects and tolerability). The final study completion date is also scheduled for May 2, 2023.

Trial NCT04713553

  • Ages included: 12 to 50
  • Number of people (all ages): 1,530
  • Clinical trial phase: Phase 3
  • What the trial is looking at: This trial is looking at safety, tolerability, and immune responses of different batches of the vaccine, along with the effectiveness of varying dose levels. A booster study will also be conducted, but only in adults age 18 years and older.
  • Kid-specific results: None posted
  • Time frame: February 15, 2021 – July 22, 2021

Trial NCT04816643

  • Ages included: 6 months to 11 years
  • Number of people (all ages): 4,500
  • Clinical trial phase: Phase 2/3
  • What the trial is looking at: Researchers are analyzing the safety, tolerability and immune responses of the COVID-19 vaccine in healthy children under the age of 12 years.
  • Kid-specific results: None posted
  • Timeframe: March 24, 2021 – April 29, 2022 (primary completion date). The final study completion date is scheduled for October 27, 2023.

Trial NCT04848584

  • Ages included: 16 and older
  • Number of people (all ages): 999
  • Clinical trial phase: Active, not recruiting
  • What the trial is looking at: The trial will analyze the effectiveness of two doses of the COVID-19 vaccine at preventing hospitalization from the virus. Researchers will also examine its effectiveness against different strains of the virus.
  • Kid-specific results: None posted
  • Timeframe: May 15, 2021 – April 1, 2022 (primary completion date). The final study completion date is scheduled for July 30, 2023.

Moderna

Trial NCT04649151

  • Ages included: 12 years to 17 years
  • Number of people (all ages): 3,732
  • Clinical trial phase: Phase 2/3
  • What the trial is looking at: This clinical trial is analyzing the safety and effectiveness of the COVID-19 vaccine in teens, along with its side effects and ability to prevent the virus.
  • Kid-specific results: A press release from Moderna issued in late May says that the vaccine is 100% effective against COVID-19 in this age group. The vaccine is also “generally well tolerated” and has “no significant safety concerns" as of now.
  • Timeframe: December 9, 2020 – June 30, 2022

Trial NCT04796896

  • Ages included: 6 months to 11 years
  • Number of people (all ages): 13,275
  • Clinical trial phase: Phase 2/3
  • What the trial is looking at: The trial will study the safety and effectiveness of this vaccine in children between the ages of 6 months and 11 years.
  • Kid-specific results: None posted
  • Timeframe: March 15, 2021 – June 12, 2023

Novavax

Trial NCT04611802

  • Ages included: 12 years and older
  • Number of people (all ages): 33,000
  • Clinical trial phase: Phase 3
  • What the trial is looking at: The trial is evaluating the safety and efficacy of the Novavax vaccine in adults 18 and up, as well as teens between the ages of 12 to 17 who are at risk of COVID-19.
  • Kid-specific results: None posted
  • Time frame: December 27, 2020 – June 30, 2023

Pfizer, Moderna, Johnson & Johnson, AstraZeneca, Sputnik

Trial NCT04832932

  • Ages included: 16 years and older
  • Number of people (all ages): 1,000
  • Clinical trial phase: Recruiting
  • What the trial is looking at: The trial is looking at potential side effects, including long-term effects of the vaccine. It’s also analyzing how many study participants develop COVID-19.
  • Kid-specific results: None posted
  • Time frame: June 15, 2021 – June 15, 2022 (primary completion date). The final completion date is scheduled for December 31, 2022.

The information in this article is current as of the date listed, which means newer information may be available when you read this. For the most recent updates on COVID-19, visit our coronavirus news page.

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Article Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Centers for Disease Control and Prevention. COVID data tracker. Updated May 10, 2021.

  2. Food and Drug Administration. Coronavirus (COVID-19) update: FDA authorizes Pfizer-BioNTech COVID-19 vaccine for emergency use in adolescents in another important action in fight against pandemic. Published May 10, 2021.

  3. Centers for Disease Control and Prevention. Vaccine testing and the approval process. Updated May 1, 2014.

  4. Pfizer. Pfizer-BioNTech announce positive topline results of pivotal COVID-19 vaccine study in adolescents. March 31, 2021.

  5. Moderna. Moderna announces TeenCOVE study of its COVID-19 vaccine in adolescents meets primary endpoint and plans to submit data to regulators in early June. Updated May 25, 2021.