(Reuters)

U.S. regulators today (May 10) authorized Pfizer and BioNTech’s COVID-19 vaccine for use in children as young as 12, widening the country’s inoculation program as vaccination rates have slowed significantly.

The vaccine has been available under an emergency use authorization (EUA) to people as young as 16 in the United States. The vaccine makers said they had started the process for full approval for those ages last week.

The U.S. Food and Drug Administration said it was amending the EUA to include the millions of children aged 12 to 15.

It is the first COVID-19 vaccine to be authorized in the United States for this age group, seen as an important step for getting children back into schools safely. U.S. President Joe Biden has asked states to make the vaccine available to the younger adolescents immediately.

“Today’s action allows for a younger population to be protected from COVID-19, bringing us closer to returning to a sense of normalcy and to ending the pandemic,” Acting FDA Commissioner Dr. Janet Woodcock said in a statement.

“Parents and guardians can rest assured that the agency undertook a rigorous and thorough review of all available data, as we have with all of our COVID-19 vaccine emergency use authorizations.”

Pfizer’s vaccine is the only one authorized for 16 and 17-year-olds in the United States. Nearly 2 million people in that age group have received at least one shot, according to Centers for Disease Control Prevention data. Many states only opened to non-high-risk individuals in that age group in early April.

Widely vaccinating 12- to 18-year olds could allow U.S. schools to relax masking and social distancing measures suggested by the CDC.

Pfizer has said it expects to have safety and efficacy data for children ages 2-to-11 in September when it plans to ask for further expansion of the EUA for that age group.