In 2022, Florida weathered a bad outbreak of meningococcal disease, a type of fast-moving bacterial infection that can become fatal after entering the bloodstream or the lining of the brain and spinal cord. As the number of ill people climbed into the dozens, public-health officials scrambled to address clusters of cases, including one among college and university students. Campuses are primed for outbreaks: The bacteria spread through the kind of intimate or prolonged contact that’s rampant on campuses, where people are “kissing and sharing drinks, being in close quarters in dorm rooms and parties,” Sarah Nosal, the president-elect of the American Academy of Family Physicians, told me. College attendance is considered its own risk factor for infection, and many states—including Florida—require the meningococcal vaccine for students living on campus.

Soon, though, Florida’s policy may change. Earlier this month, the state’s surgeon general, Joseph Ladapo, announced his intention to end all vaccine mandates: “Every last one of them is wrong,” he said …

If vaccination rates fall—due to changing federal recommendations, states eliminating mandates, increasing anti-vaccine sentiment, or some combination of all of the above—middle schools, high schools, and college campuses may also become particular breeding grounds for once-controlled illnesses.