• Video
  • Shop
  • Culture
  • Family
  • Wellness
  • Food
  • Living
  • Style
  • Travel
  • News
  • Book Club
  • Newsletter
  • Privacy Policy
  • Your US State Privacy Rights
  • Children's Online Privacy Policy
  • Interest-Based Ads
  • Terms of Use
  • Do Not Sell My Info
  • Contact Us
  • © 2026 ABC News
  • Wellness

Pfizer launches COVID vaccine trial for kids under 12

3:02
Pfizer tests its vaccine on younger children, starting with those age 5 to 11
Curtis Compton/Atlanta Journal-Constitution via AP
ByDr. Tarun Jain and Sony Salzman
March 25, 2021, 4:31 PM

Pfizer now joins Moderna in testing its vaccine in younger children.

The company will enroll 4,500 children in a trial that will ultimately include children as young as 6 months old. Previous trials have studied children ages 12 years and older.

Related Articles

MORE: Map shows which states offer COVID-19 <a href="https://abcnews.com/alerts/vaccinations" id="_ap_link_vaccines_Vaccinations_" target="_blank">vaccines</a> to everyone

Experts say it's important to specifically test vaccines in children to ensure they are safe and effective in the youngest members of society -- so that ultimately everyone is eligible to receive a potentially life-saving vaccine.

The trial is also important for protecting children from severe COVID-19 infection or complications from an infection, said Dr. Emmanuel Walter, chief medical officer of the Duke Human Vaccine Institute. Duke University is one of several medical centers participating in the Pfizer trial.

Anita Shetty M.D. gives 17-year-old cancer survivor Jordan Loughan a Pfizer vaccination, March 23, 2021, in Atlanta.
Curtis Compton/Atlanta Journal-Constitution via AP

"If you look at the number of pediatric deaths reported in the last year, it actually exceeds that for influenza in any influenza season that we generally see," Walter said.

Three phases will study different aspects of the vaccine. The first phase will find an ideal dose for children, with the following two phases studying vaccine safety and efficacy.

"We always worry that side effects may be different in young children. They're not just little adults," said Walter.

On Wednesday, Marisol and Alejandra Gerardo were the first participants in the Pfizer trial.

Related Articles

MORE: Hang on to that COVID-19 vaccination card -- it's important

"I think we're super excited that this is an opportunity for us to both potentially get our kids access, but also to contribute to knowledge of how safe this is for kids," said Dr. Susanna Naggie, mother of Marisol and Alejandra.

Other vaccine manufacturers have also been hard at work moving to offer their vaccines to children. Moderna announced on March 16 that it would enroll 6,750 children ages 6 months to 12 years in a clinical trial. Johnson & Johnson has announced its intentions to develop trials for children. Meanwhile, AstraZeneca, which announced encouraging phase III trial results this week in the United States, has been studying children ages 6 and older in the United Kingdom since February.

Related Articles

MORE: Pfizer vaccine shows 94% effectiveness against asymptomatic transmission of COVID

Naggie noted that her children did well. While getting the injection, Alejandra told her mother, "That feels good!"

Tarun Jain, MD, is a chief resident physician in internal medicine and pediatrics and a member of the ABC News Medical Unit.

Up Next in Wellness—

Adolescent and young adult cancers increase risk of developing future cancers

April 13, 2026

Teen with kidney disease finds donor living minutes away

April 10, 2026

Her battle with cancer went viral. After her death, the impact of her advocacy is still felt

April 8, 2026

Gabrielle Union shares emotional tribute after dad dies following dementia battle

April 6, 2026

Shop GMA Favorites

ABC will receive a commission for purchases made through these links.

Sponsored Content by Taboola

The latest lifestyle and entertainment news and inspiration for how to live your best life - all from Good Morning America.
  • Contests
  • Terms of Use
  • Privacy Policy
  • Do Not Sell My Info
  • Children’s Online Privacy Policy
  • Advertise with us
  • Your US State Privacy Rights
  • Interest-Based Ads
  • About Nielsen Measurement
  • Press
  • Feedback
  • Shop FAQs
  • ABC News
  • ABC
  • All Videos
  • All Topics
  • Sitemap

© 2026 ABC News
  • Privacy Policy— 
  • Your US State Privacy Rights— 
  • Children's Online Privacy Policy— 
  • Interest-Based Ads— 
  • Terms of Use— 
  • Do Not Sell My Info— 
  • Contact Us— 

© 2026 ABC News