Pfizer: Vaccine Shown 100% Effective in Kids 12-15

Ralph Ellis

March 31, 2021

Phase III clinical trials show that Pfizer's coronavirus vaccine is 100% effective in protecting children 12-15 years old from infection, the company said in a news release.

The study enrolled 2,260 adolescents ages 12-15. No infections were reported in the group given the vaccine produced by Pfizer and its European partner, BioNTech, the release said. The placebo group reported 18 cases of COVID-19, it said.

The vaccinated children showed a strong antibody response with no serious side effects.

Albert Bourla, PhD, chairman and CEO of Pfizer, said the company plans to seek FDA emergency use authorization, which could allow this age group to be vaccinated before the start of the next school year. Pfizer will also seek authorization from the European Medicines Agency.

"We share the urgency to expand the authorization of our vaccine to use in younger populations and are encouraged by the clinical trial data from adolescents between the ages of 12 and 15," Bourla said in the release.

The clinical trials showed a stronger response in children 12-15 than the 95% effectiveness reported in clinical trials in adults. The Pfizer vaccine is now authorized to be given to people 16 and up in the United States.

Health experts said the clinical trials — while not peer-reviewed — were very good news.

"The sooner that we can get vaccines into as many people as possible, regardless of their age, the sooner we will be able to really feel like we're ending this pandemic for good," Angela Rasmussen, PhD, a virologist affiliated with Georgetown University in Washington, told The New York Times.

Anthony Fauci, MD, director of the National Institute of Allergy and Infectious Diseases, recently said that getting children vaccinated is an important step toward achieving herd immunity.

"We don't really know what that magical point of herd immunity is, but we do know that if we get the overwhelming population vaccinated, we're going to be in good shape," he said earlier in March during a hearing of the Senate Health, Education, Labor, and Pensions Committee. "We ultimately would like to get and have to get children into that mix."

Pfizer said it started clinical trials last week on children ages 5-11 and will next start trials on children 2-5, followed by children ages 6 months to 2 years. Vaccine makers Moderna and AstraZeneca have also started clinical trials in younger children.


Pfizer: "Pfizer-BioNTech Announce Positive Topline Results Of Pivotal Covid-19 Vaccine Study In Adolescents."

The New York Times: "The Pfizer-BioNTech Vaccine Is Said to Be Powerfully Protective in Adolescents."