WASHINGTON (AP) — A review by federal health officials finds that Pfizer’s COVID-19 vaccine appears safe and effective for children under 5, the only group not currently eligible for vaccination.

The review issued Sunday by the Food and Drug Administration is a key step toward a decision on vaccinations for babies, toddlers and preschoolers, perhaps as soon as June 21. Parents have been waiting months to protect America’s youngest children, who number roughly 18 million.

The FDA said children who received the kid-sized shots developed a strong immune response to help fight off the coronavirus. That’s the requirement needed to win FDA authorization.

Late last week the FDA posted a similar analysis of Moderna’s shots for children under 6.

On Wednesday, the FDA will ask an outside panel of experts to vote on whether to recommend the two companies’ shots.