Moderna said Monday that a low dose of its COVID-19 vaccine is safe and appears to work in 6- to 11-year-olds, as the manufacturer moves toward expanding shots to children.

Competitor Pfizers kid-sized vaccine doses are closer to widespread use, undergoing evaluation by the Food and Drug Administration for nearly the same age group starting at age 5. Its vaccine already is authorized for anyone 12 or older.

Moderna hasnt yet gotten the nod to offer its vaccine to teens but is studying lower doses in younger children while it waits. Researchers tested two shots for the 6- to 11-year-olds, given a month apart, that each contained half the dose given to adults.