The Pfizer / BioNTech COVID-19 vaccine can now be administered to 12- to 15-year-olds, the Food and Drug Administration announced today. Previously, the shot was authorized for people 16 years of age and older.

The companies asked the FDA to expand the authorization to include the new ages in early April, just after they released data showing that their vaccine was highly effective for that group. All of the 12- to 15-year-olds given the two-dose vaccine in a small study generated strong antibody response with no serious side effects, and none developed COVID-19.

Later this week, a committee from the Centers for Disease Control and Prevention will meet to make recommendations on how the vaccine should be rolled out to this age group.

The United States will likely need to vaccinate kids and teenagers to reach herd immunity and end the pandemic — the expanded authorization is another step toward that goal.

“Having a vaccine authorized for a younger population is a critical step in continuing to lessen the immense public health burden caused by the COVID-19 pandemic,” said Peter Marks, director of the FDA’s Center for Biologics Evaluation and Research, in a statement.

Although kids are less likely to get seriously sick from COVID-19 than adults, they can still catch the virus and suffer long-term symptoms. If they’re infected with the virus, they can also pass it along to others, so vaccinating kids is a way to stop them from getting family members or others sick. Approximately 1.5 million people in the US between the ages of 11 and 17 have gotten COVID-19 since March 2020.

Pfizer and BioNTech also have studies in progress testing their COVID-19 vaccine in younger age groups, starting with infants six months old. Moderna, which has a COVID-19 vaccine authorized for people 18 years and older, is testing its shot in children and adolescents aged six months through 17 years old. Johnson & Johnson has plans for similar studies, as well.

152,819,904 people in the US have received at least one shot of a COVID-19 vaccine.