The Food and Drug Administration authorized the emergency use of the Pfizer-BioNTech coronavirus vaccine for 12- to 15-year-old adolescents, the agency announced on Monday.

Why it matters: The emergency authorization marks a critical milestone in the push to get more Americans vaccinated and fully reopen schools for in-person learning this fall.

• Pfizer has said its vaccine was 100% effective at protecting against COVID-19 in a trial of more than 2,200 children between the ages of 12 and 15.

What they're saying: “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. Parents and guardians can rest assured that the agency undertook a rigorous and thorough review of all available data," said acting FDA Commissioner Janet Woodcock.

The big picture: Children are at low risk for serious illness from COVID-19, but experts say allowing the virus to circulate among unvaccinated kids could lead to new, more dangerous variants and slow down the protection of adults.

• Still, about 1.5 million COVID-19 cases in individuals 11–17 years of age have been reported to the Centers for Disease Control and Prevention since the beginning of the pandemic.
• The FDA has already authorized Pfizer's vaccine for people 16 and older. Moderna and Johnson & Johnson also have trials for teens underway.

Yes, but: Parents' enthusiasm for the incoming emergency use authorization has so far been mixed, even among those who themselves have been vaccinated.

• Only 52% of parents of a child under 18 said they’re likely to vaccinate their kids as soon as they're eligible, according to an Axios/Ipsos survey from April.
• In a separate survey from KFF, 32% of parents said they'll wait to see how the vaccine works before getting their child vaccinated, and 19% said they definitely wouldn't get their child vaccinated. 

What's next: A CDC advisory committee will meet Wednesday to review the data and make recommendations for the vaccine’s use in 12- to 15-year-olds.

• Moderna is expected to announce trial results for adolescents aged 12–17 in the second half of 2021, the New York Times reports.