BNTX BioNTech SE

By Jared S. Hopkins and Peter Loftus 

Covid-19 vaccines from Pfizer Inc. and Moderna Inc. are edging closer to use in young children.

Pfizer and partner BioNTech SE said Tuesday that they have begun testing their vaccine in children under 12 years old in a pivotal study. If the results prove positive, Pfizer said it would ask U.S. health regulators in September to expand use to some of the younger children.

Meantime, Moderna Chief Executive Stephane Bancel said results of testing Moderna's vaccine in children as young as five years could become available by the fall, which if positive could lead to regulatory authorization of its use in the younger age group.

The Pfizer-BioNTech vaccine is available for children as young as 12 years, while Moderna's vaccine is authorized for use in people 18 years and older.

Moderna, of Cambridge, Mass., is seeking regulatory approval for its use in children 12 to 17 years in some countries but not yet the U.S., after reporting a positive study in adolescents in May. The company has said it plans to seek regulatory clearance for adolescent use in the U.S.

Moderna started a study of its vaccine in children under 12 years in March, and could have results in September or October, Mr. Bancel said at an event hosted by social-networking app Clubhouse.

Children are at lower risk of Covid-19 infection than adults, according to health experts, and when they are infected, they tend to experience milder symptoms.

Yet some can become seriously ill, and some can spread the virus. Health authorities are seeking vaccination of children to protect them and for the development of communitywide, or herd, immunity that would allow for a return to a more normal life.

"If successful, we believe vaccinating children will help further protect our communities and contribute to the evolving herd immunity," said Dr. Bill Gruber, senior vice president of clinical research and development at Pfizer.

About 6.8 million children 12 years to 17 years have received at least one dose of a vaccine in the U.S., of whom about 3 million are fully vaccinated, according to the U.S. Centers for Disease Control and Prevention.

Pfizer and BioNTech began the early stage, or Phase 1, portion of their young-children vaccine trial in March.

Pfizer and BioNTech didn't provide any data from the study on the shot's safety or ability to protect against Covid-19, but said the results were sufficient to move forward into later-stage, or Phase 2/3, testing.

Based on the Phase 1 portion of the study, researchers selected different two-dose regimens for 5 to 11-year-olds and for children six months to below the age of five, the companies said.

The dosage levels are lower than those for the shots given to adults and children as young as 12 years old.

The companies said they have already begun enrolling children who are 5 to 11 years old, and in a few weeks will begin enrolling children between 6 months and under 5 years.

Altogether, Pfizer plans to enroll up to 4,500 children at more than 90 locations in the U.S., Finland, Poland and Spain.

Pfizer expects data for children between the ages of 5 and 11 in September and, if positive, could potentially submit for an authorization later that month, a company spokesman said.

Data for children from 2 to 5 years could arrive soon after that, the spokesman said. For children between 6 months and 2 years, data could come in October or November, with an emergency use authorization to follow, the spokesman said.

Write to Jared S. Hopkins at jared.hopkins@wsj.com and Peter Loftus at peter.loftus@wsj.com

(END) Dow Jones Newswires

June 08, 2021 12:27 ET (16:27 GMT)

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