(NewsNation Now) — Several U.S. colleges and universities hoping to get back to normal campus life after months of online learning announced they plan to require COVID-19 vaccinations for all students and faculty before the fall semester.

The University of California and California State University, two of the nation’s largest university systems, announced Thursday they intend to require vaccinations for all students, faculty, and staff on campuses this fall.

CSU spokeswoman Toni Molle said the timing of a formal mandate will depend on when the FDA gives full authorization to one or more of the vaccines and also on discussions with labor unions. It could come before or after classes start.

“We are announcing now so that students and employees have time to receive a vaccination” by fall, when the proposed policy would take effect, she said.

The two systems have said they expect the majority of instruction and activities in fall 2021 to be in-person.

Stanford University also announced a mandate Thursday for all of its 19,000 students to be vaccinated when classes start in the fall. At the private school, students who have an approved vaccination exemption for medical or religious reasons will be required to undergo regular COVID-19 testing.

In Massachusetts, the private Amherst College announced students must be vaccinated by the fall semester. Meanwhile, in North Carolina, the University of North Carolina at Chapel Hill is not mandating vaccines, yet private universities in the state, like Duke University, are.

University of California Law Professor Dorit Reiss says she’s not surprised to see this divide.

“Public institutions are subject to the state and federal constitution. Private institutions don’t usually have to respect constitutional rights,” Reiss explained.

Meanwhile, courts are preparing for legal challenges and pushback to mandating.

Alison Triessl, a California lawyer, says that the courts have spoken on this, emergency use or not.

“There is United States Supreme Court precedent that allows for mandatory vaccinations to protect the public,” Triessl said.

On the other hand, Reiss says that the schools may face backlash for not doing enough.

“So, at least in theory, you could see people suing universities public or private for not protecting students against outbreaks,” Triessl said.

There is agreement, however, that both public and private institutions, in every state, all just want to return to campus next fall.

Universities including the University of Michigan, Rutgers, Brown, Cornell, and Northeastern recently told students they must get vaccinated before returning to campus next fall. They hope to achieve herd immunity on campus, which they say would allow them to loosen spacing restrictions in classrooms and dorms.

But some colleges are leaving the decision to students, and others believe they can’t legally require vaccinations. At Virginia Tech, officials determined that they can’t because the FDA has only allowed the emergency use of the vaccines.

Many schools have launched vaccination blitzes to get students immunized before they leave for the summer.

Northeastern and other colleges requiring shots believe they’re on solid legal ground. It’s not unusual for colleges to require students to be vaccinated for other types of diseases, and a California court last year upheld a flu shot requirement at the University of California system.

The Associated Press contributed to this report.