Hundreds of New York City correction officers will be placed on unpaid leave after refusing to comply with a newly enacted vaccine mandate.

Department of Correction employees were given until Tuesday afternoon to get their first shot of the COVID-19 vaccine, a one-month extension on the deadline for all other municipal workers. The deferred implementation was intended to avoid inflaming the staffing crisis that has thrown Rikers Island into chaos in recent months.

Despite the added time, 23% of uniformed correction officers — or close to 2,000 people — remained unvaccinated on Wednesday, according to City Hall. Another 700 unvaccinated guards will be allowed to continue working as they await a response on their medical exemption applications.

The vaccination rates, among the lowest of any city agency, represent a significant jump from two weeks ago, when just 63% of uniformed correctional staff had received the vaccine. At a press conference on Wednesday, de Blasio said he expected the inoculation rate to further increase in the aftermath of the deadline, as has been the case with other agencies, including the FDNY and the NYPD.

“We've seen it with every agency, there’s a certain number of days where things need to sort out, and it's going to happen here,” de Blasio said.

Still, the loss of jail staff is expected to exacerbate dire conditions on Rikers Island, where hundreds of correction officers have continued to skip work, despite the mayor’s efforts to end the apparent work stoppage.

In recent months, roughly a third of the agency’s 8,400 uniformed staff were unavailable to work with the incarcerated population, contributing to a breakdown in jail operations that saw surging rates of violence and an inability to properly quarantine infected detainees.

Exposures and confirmed cases of COVID-19 have trended downward in the last month. But health officials have also warned that the winter weather, and looming threat of the omicron variant, could quickly fuel a resurgence in tightly-packed city jails.

“If you want to prevent a wave, a surge or ripples, correction officers need high immunity,” said a healthcare provider on Rikers Island, who was not authorized to speak on the record, told WNYC/Gothamist.

Ahead of the vaccine mandate deadline, the Department of Correction announced plans to move to 12-hour shifts to ensure adequate staffing — a temporary measure opposed by the correction officers' union. In a statement this week, the Correction Officers Benevolent Association said the move would "wreak complete havoc" on both staff and detainees.

At a press conference on Wednesday, Correction Commissioner Vincent Schiraldi acknowledge the added strain on jail staff, calling it a temporary measure.

Even with the increase in overtime, Schiraldi added, portions of the jail complex remain unstaffed. But he added that violence and use-of-force rates have begun to decline from their late summer high, as the population at Rikers has decreased from more than 6,000 to roughly 5,200 people now.