A group of visitors take a selfie near a sign reading "stay 6 feet apart at all times," Thursday, May 6, 2021, on the University of Chicago campus in Chicago. Even as restrictions relax across much of the United States, colleges and universities have taken new steps to police campus life as the virus spreads through students who are among the last adults to get access to vaccines. (AP Photo/Shafkat Anowar)

FILE - In this Feb. 3, 2021, file photo, Jazmyn Finney, seated, is administered a coronavirus rapid test by a certified medical assistant at the student health center on campus at North Carolina Agricultural and Technical State University in Greensboro, N.C. Even as restrictions relax across much of the United States, colleges and universities have taken new steps to police campus life as the virus spreads through students who are among the last adults to get access to vaccines. (AP Photo/Gerry Broome)

Students wearing masks make their way through the University of Chicago campus, Thursday, May 6, 2021, in Chicago. Even as restrictions relax across much of the United States, colleges and universities have taken new steps to police campus life as the virus spreads through students who are among the last adults to get access to vaccines. (AP Photo/Shafkat Anowar)

Students and pedestrians make their way through the University of Chicago campus, Thursday, May 6, 2021. Even as restrictions relax across much of the United States, colleges and universities have taken new steps to police campus life as the virus spreads through students who are among the last adults to get access to vaccines. (AP Photo/Shafkat Anowar)

University of Chicago sophomore Silvana Montagu, right and Sonny Lee take advantage of warm spring weather as they spend time in a hummock Thursday, May 6, 2021, in University of Chicago. Even as restrictions relax across much of the United States, colleges and universities have taken new steps to police campus life as the virus spreads through students who are among the last adults to get access to vaccines. (AP Photo/Shafkat Anowar)

FILE - In this April 8, 2021, file photo, students exit the KSU Ice Arena after getting their Johnson & Johnson COVID-19 vaccination at Kent State University in Kent, Ohio. Even as restrictions relax across much of the United States, colleges and universities have taken new steps to police campus life as the virus spreads through students who are among the last adults to get access to vaccines. (AP Photo/Phil Long, File)

FILE - In this May 6, 2021, file photo, University of Chicago men's rugby team players practice on the Midway Plaisance near the campus in Chicago. Even as restrictions relax across much of the United States, colleges and universities have taken new steps to police campus life as the virus spreads through students who are among the last adults to get access to vaccines. (AP Photo/Shafkat Anowar, File)

FILE - In this April 8, 2021, file photo, Kent State University student Jarrett Woo gets his Johnson & Johnson COVID-19 vaccination from Kent State nursing student Allie Rodriguez in Kent, Ohio. Even as restrictions relax across much of the United States, colleges and universities have taken new steps to police campus life as the virus spreads through students who are among the last adults to get access to vaccines. (AP Photo/Phil Long, File)

FILE - In this April 26, 2021, file photo, Johnson Shao, a nursing student at the College of Southern Nevada, administers the Moderna COVID-19 vaccine at a vaccination center at UNLV in Las Vegas. Even as restrictions relax across much of the United States, colleges and universities have taken new steps to police campus life as the virus spreads through students who are among the last adults to get access to vaccines. (AP Photo/John Locher)