WASHINGTON — US First Lady Jill Biden on Monday visited a school in Virginia to promote vaccinations for five- to 11-year-olds, the latest effort in the White House’s push to combat the Covid-19 pandemic.

The president’s wife, a university professor, was the first senior personality sent out to advocate for the vaccine since it was approved for younger children in the United States on November 2.

Visiting Franklin Sherman Elementary School in McLean, Virginia, not far from Washington, Biden handed out stickers to students who had already been vaccinated and encouraged the audience to applaud them.

But her message was mainly directed at parents in a school that was, according to the White House, the first in the United States to administer the polio vaccine in 1954.

“Nothing is more important than our children’s health,” she said. “It’s up to us to keep them safe — and with this vaccine, we can.”

Some 28 million children aged between five and 11 are now eligible to receive Pfizer-BioNTech’s vaccine against Covid-19 in the United States.