Stockton University in South Jersey is now the latest higher education institution in the state requiring students to get the COVID-19 vaccine ahead of the fall semester.

Students will be required to get the vaccine if they want to return to campus, reads a university-wide letter from Stockton President Harvey Kesselman sent out on May 5.

The shot is optional for faculty and staff, but Kesselman estimated that 35% of those working for Stockton have already gotten the vaccine.

“One of the most important steps we all can take to keep ourselves and each other safe is to get vaccinated. It is the responsible thing to do,” he said in the Wednesday evening email. “The COVID-19 vaccine is now plentiful and available to everyone over the age of 16.”

The New Jersey Institute of Technology, Princeton, Rutgers, Montclair State University, Stevens Institute of Technology and Fairleigh Dickinson University are requiring students to get vaccinated if they want to return to campus this fall, while the New Jersey Performing Arts Center will require patrons to show proof that they’ve been vaccinated or tested negative for COVID-19 in the past three days.

All told, 13 of the state’s 28 colleges and universities are now requiring the vaccine.

The Murphy administration is aiming to fully vaccinate 4.7 million adults by June 30, of which more than 3.2 million people are fully inoculated.

State health officials contend that threshold is key to building widespread herd immunity that could curtail the spread of the virus, and in turn, lead to lifting COVID-19 business restrictions en masse. Most of the delivered shots are from the two-dose Pfizer or Moderna vaccines, and a small percentage from the one-shot Johnson & Johnson inoculation.

Because of the limited J&J presence and the two-dose requirement for Pfizer and Moderna, spaced roughly a month apart, Murphy admitted on May 5 that “end of May, early June” is when the state will really know if it’s met its herd immunity goal.

Interest in getting the vaccine has lagged recently, despite increasingly abundant dosage supply, and state officials are ramping up their efforts to reach those remaining 1.3 million New Jerseyans with an aggressive marketing campaign, which includes free beer at 34 select breweries for anyone over the age of 21 who gets their first shot this May.

Called “Operation Jersey Summer,” the campaign launched on May 3 to reach the arms of remaining adults who have been hesitant to get the vaccine. It includes more walk-in appointments, a 30-second video contest, automated goals and email messages, and field campaigns.