Anthony Fauci, the top U.S. infectious disease expert, said state and local governments should require teachers to get vaccinated against COVID-19.

As back-to-school season approaches and the delta variant surges across the U.S., Fauci acknowledged that his position might anger some people who’ve resisted vaccine mandates for teachers.

“Yeah I’m going to upset some people on this, but I think we should,” he said today in an interview with MSNBC. “This is very serious business. You would wish that people would see why it’s so important to get vaccinated.”

But Fauci, director of the National Institute of Allergy and Infectious Diseases, said there wouldn’t be federal mandates for teacher vaccinations. Local mandates “for schools, for teachers, for universities, for colleges” would be appropriate, he said.

“I’m sorry, I mean I know people must like to have their individual freedom and not be told to do something, but I think we’re in such a serious situation now, that under certain circumstances, mandates should be done,” he said.

Full Food and Drug Administration approval could help empower governors and local officials to institute vaccine mandates without fear of legal repercussions, Fauci said.

“Local enterprises,” he said, also could feel they have more latitude to require vaccines following full FDA approval.

“If you want to work in an organization, you have to be vaccinated: I think we’re going see a lot more of that,” Fauci said.

Fauci’s comments coincide with rising tensions across the country between state governments and school districts over mask and vaccine requirements as schools plan to open.

Florida Governor Ron DeSantis is threatening to withhold pay from local school officials who defy his executive order banning classroom mask mandates.

The Defense Department has announced that it will make COVID-19 vaccinations mandatory for members of the U.S. military by Sept. 15.