This is the first coronavirus vaccine in the United States authorized for use in younger teens and adolescents; the vaccine had previously been authorized for people age 16 and older. Covid-19 vaccines from Moderna and Johnson & Johnson are authorized for use in people age 18 and older.

To support the extended use, the FDA reviewed data submitted by Pfizer. The company said at the end of March that a clinical trial involving 2,260 12-to-15-year-olds showed the vaccine's efficacy is 100 percent and it is well tolerated.

The FDA's independent Vaccines and Related Biological Products Advisory Committee did not meet to vote on whether to recommend the expansion of the EUA to 12-to-15-year-olds. But the US Centers for Disease Control and Prevention's Advisory Committee on Immunization Practices is scheduled to meet Wednesday to advise CDC on whether to recommend the use of the vaccine in this age group. CDC Director Dr. Rochelle Walensky will then decide whether the agency will recommend the vaccine's use in the new group.

Vaccinations for 12-to-15-year-olds are not expected to begin until after that recommendation. The Biden administration has said it will quickly mobilize to ready vaccinations for 12-to-15-year-olds through the federal pharmacy program, pediatricians and family doctors.

Expanding authorization to people 12 to 15 opens COVID-19 vaccination to another 5 percent of the US population, nearly 17 million more people. The expanded authorization means 85 percent of the US population is eligible to receive a COVID vaccine.

Pfizer said last week it expects to submit for emergency use authorization for its COVID-19 vaccine for children ages 2 to 11 years old in September. Its vaccine safety and efficacy study in children ages 6 months to 11 years old is ongoing.

The FDA also scheduled a meeting of its Vaccines and Related Biological Products Advisory Committee for June 10 to discuss the potential extension of EUA to children under 12.

"During the meeting, the agency will provide a status update on our approach to emergency use authorization (EUA) for COVID-19 vaccines intended for use in individuals 12 through 17 years of age," the FDA said in a statement.

"The committee will also discuss the data needed to support a EUA and a biologics license application (BLA) for a COVID-19 vaccine intended for use in children less than 12 years of age. The committee will not discuss any specific products," it added.

Vaccines made by Moderna and by Johnson & Johnson are currently authorized for use in people 18 and older.

"We recognize that the next critical step is having vaccines available for use throughout the pediatric population," Dr. Peter Marks, head of the FDA division in charge of vaccines, said in a statement.

"As with the initial COVID-19 vaccine authorizations, we want to ensure that the public has a clear understanding of our expectations for the data and information needed to support requests for emergency use authorization and biologics license applications for vaccines intended to prevent COVID-19 in this pediatric age range." — CNN