Moderna, the company behind one of the FDA-approved, two-dose COVID-19 vaccines, is hoping its vaccine can help children.

On Tuesday, the company announced that participants have received their first dose in a new trial focused on children under the age of 12.

Moderna is calling this Phase 2/3 study the “KidCOVE” study of mRNA-1273, the company’s vaccine candidate against COVID-19.

“We are pleased to begin this Phase 2/3 study of mRNA-1273 in healthy children in the U.S. and Canada and we thank NIAID and BARDA for their collaboration,” said Stéphane Bancel, chief executive officer of Moderna. “It is humbling to know that 17.8 million adults in the U.S. have received the Moderna COVID-19 vaccine to date. We are encouraged by the primary analysis of the Phase 3 COVE study of mRNA-1273 in adults ages 18 and above and this pediatric study will help us assess the potential safety and immunogenicity of our COVID-19 vaccine candidate in this important younger age population.”

The study will look at the safety, tolerability, effectiveness and possible reactions of two doses of mRNA-1273 given 28 days apart.

Moderna plans to enroll about 6,750 children between the ages of 6 months and 12 years across the U.S. and Canada.

In the first part of this study, Moderna is working with participants between the ages of 2 years to less than 12 years. Each child may receive one of two dose levels. Each participant ages six months to less than 2 years may receive one of three dose levels, include the two tested with older ages as well as one that is a lower dosage.

Modern will continue following participants through 12 months after the second vaccination.

The company expects to be able to use the results of this study to determine if the vaccine is also effective for people ages 18 to 25.