Dr. Anthony Fauci says COVID-19 vaccines should be mandatory for schoolteachers, citing the need to protect children who are too young to be vaccinated during a pandemic that has grown worse with the spread of the delta variant.

"I'm going to upset some people on this, but I think we should [require teacher vaccinations]," Fauci said Tuesday morning in an interview on MSNBC.

"I mean, we are in a critical situation now," he said. "We've had 615,000-plus deaths, and we are in a major surge now as we're going into the fall, into the school season. This is very serious business."

Mandates will spread when vaccines get full approval

The mandates won't come from the federal level, said Fauci, director of the National Institute of Allergy and Infectious Diseases who is also President Biden's chief medical adviser on COVID-19.

Instead, he said, the vaccine requirements will come at the state and local levels — and Fauci predicted they'll proliferate when the Food and Drug Administration gives full approval to coronavirus vaccines, rather than their current status of being authorized for emergency use.

"It's gonna happen. Guaranteed it's gonna happen," Fauci said of the FDA's full approval, adding he hopes it happens "very soon."

For now, people who refuse to get vaccinated because of that discrepancy are seizing on a technicality, Fauci said.

"There's no doubt that these vaccines are going to get fully approved," he said. "This idea about, 'It's not fully approved,' is really a false narrative. It really is. I mean, you should consider this as good as fully approved and get vaccinated."

Teachers unions are showing less opposition to mandates

Fauci's remarks echo the sentiments of Randi Weingarten, president of the American Federation of Teachers, who said over the weekend that her union should be working with school districts on vaccine mandates, rather than opposing them outright.

"It weighs really heavily on me that kids under 12 can't get vaccinated," Weingarten said, calling vaccination "a community responsibility."

Weingarten said her union's leaders are meeting this week to look at revising the union's policy from last fall when it said vaccine guidelines for teachers should be voluntary rather than mandatory.

The National Education Association's Kim Anderson, executive director of the largest U.S. teachers union, recently told NPR that it's also reviewing its stance on a vaccine mandate. Both unions said that around 90% of their teachers have already gotten a COVID-19 vaccine.

New surge puts focus on kids who can't be vaccinated

With millions of students now beginning to return to school for in-person classes, Fauci stressed that teachers and education officials have two main tools for protecting children who are not eligible to receive the vaccine. One step is for everyone to wear masks. The other step should be treated as a duty of school staff, he said.

"Anyone who's eligible for a vaccine, if you want to be around children, you've got to do whatever you can to protect them. And if you're eligible to get vaccinated, get vaccinated," Fauci said.

Even before the U.S. summer coronavirus surge, children were accounting for a rising proportion of new coronavirus cases in part due to high vaccination rates among adults.

But with the country now enduring a new spike in infections due to the delta variant, children are also contracting the coronavirus at a higher rate in terms of raw numbers, according to the latest data compiled by the American Academy of Pediatrics.

Children still make up a small percentage of the people who experience the worst outcomes of COVID-19, according to the pediatric association, which said kids represented between 0% and 0.26% of all COVID-19 deaths in the more than 43 U.S. states and territories that report that specific data.

Copyright 2021 NPR. To see more, visit https://www.npr.org.