Infants and preschoolers in the U.S. will soon be able to get a COVID-19 vaccine.

The Food and Drug Administration (FDA) approved Friday the first COVID-19 shots for children under five.

Their emergency use authorization allows Moderna and Pfizer to start shipping millions of preordered doses across the country.

The FDA said vaccinations for this age group are expected to begin next week.

A final sign-off from the Centers for Disease Control and Prevention is expected this weekend.

Moderna and Pfizer use the same technology but there are differences.

Moderna’s is two shots, each a quarter of its adult dose, given about four weeks apart for kids under six.

Pfizer’s vaccine for kids younger than five is one-tenth of the adult dose. Three shots are needed, with the first two given three weeks apart and the last at least two months later.

Children as young as six months old are eligible for these vaccines.