WASHINGTON: The United States could start vaccinating older children against Covid-19 by the fall and younger ones by year-end or early 2022, the White House’s top pandemic advisor Anthony Fauci said Sunday.

The mass vaccination of school-age children will allow millions of children to return sooner to in-person learning and ease the burden on millions of parents now caring for their offspring at home.

School reopenings, an intensely debated matter, have varied sharply across the country, with some private and religious schools opening before public schools and teachers in some areas protesting any early return.

But the decision Saturday by the US Food and Drug Administration to grant emergency use authorization to a new single-dose vaccine from Johnson & Johnson has boosted the prospects for earlier reopenings.

“We now have three really efficacious vaccines,” Fauci said on ABC’s “This Week.”

For now, none of the three authorized vaccines in the US (also including Pfizer/ BioNTech and Moderna) has been cleared for children under 16, but trials on children are under way.

Children in high school — roughly ages 14-18 in the United States — should be able to get the vaccine “sometime this fall,” Fauci told NBC’s “Meet the Press.” “I’m not sure it’ll exactly be on the first day that school opens, but pretty close to that,” he added.