By Peter Szekely

NEW YORK (Reuters) – New York City officials on Friday were preparing for shortages of firefighters, police officers and other first responders as a showdown looms between the city and its unvaccinated uniformed workforce, who face a 5 p.m. EDT (2100 GMT) deadline to be immunized.

Leaders of unions representing firefighters and police officers have said more than one-third of their members could be sent home on unpaid leave when enforcement of the COVID-19 vaccine mandate takes effect on Monday.

“If you’re going to take a third of the ambulances off-line, if you’re going to take a third of the engine companies off-line, you’ll without question increase response times and increase the rate of death,” Uniformed Firefighters Association Andrew Ansbro told NY1 TV on Friday.

But Democratic Mayor Bill de Blasio, who announced the mandate nine days ago, said officials were prepared to manage any staffing gaps with overtime and schedule changes and by enlisting private ambulance companies to cover for the city’s paramedics.

Discussing those moves with reporters on Thursday, the mayor pointed out that the city also faced staffing shortages last year when many first responders were infected with the coronavirus.

The dispute in the United States’ most populous city was the latest chapter in a series of clashes across the country over public and private vaccination mandates.

New York City uniformed workers, including sanitation workers, have staged several protests this week, including one on Thursday at the mayor’s official residence. Many have said consideration should be given for the so-called natural immunity of those who have had COVID, which the firefighters’ union says includes 70% of its members.

City health officials have said that while research has yet to determine the degree of immunity that previous COVID infections yield, it is widely agreed that vaccines increase protection – even for those who have been infected.

De Blasio said only 76% of the uniformed workers facing the mandate deadline have gotten at least one dose of a vaccine, as compared with 86% of city workers overall. Within that group, he said the lowest rate was among Fire Department employees at 64%, while nearly three-quarters of police employees have complied.

He stressed, however, that he expects those rates to rise significantly by Monday.

The mayor pointed to earlier mandate deadlines for other New York state and city workers that prompted a rush for last-minute vaccinations by healthcare and education workers as the reality set in that their paychecks were about to stop coming.

“And then suddenly it becomes really clear what they have to do,” de Blasio told reporters on Thursday.

By the time a vaccination requirement for state healthcare workers kicked in on Sept. 27, Governor Kathy Hochul reported that 92% of hospital employees had gotten at least one dose and 85% were fully vaccinated, up from 77% a month earlier.

Thousands of city teachers and other school employees also waited until the final days before an Oct. 1 deadline, de Blasio said, with 96% of the them currently vaccinated.

Police and fire unions have filed lawsuits against the mandate. The Police Benevolent Association of the City of New York, which represents 24,000 police officers, lost a bid earlier this week for a court order to halt the deadline, but has taken its request to a state appeals court where it is still pending.

The courts have generally not been sympathetic to efforts to block vaccine mandates.

U.S. Supreme Court Justice Sonya Sotomayor rejected a request by four teachers and teaching assistants to block the city’s Oct. 1 mandate for school workers. And Justice Amy Coney Barrett in August denied a bid by Indiana University students to block that school’s vaccine mandate.

In Chicago, a federal judge was expected to rule on Friday on a request by a group of firefighters and other city workers for a court order to halt vaccine mandates ordered by Mayor Lori Lightfoot and Illinois Governor J.B. Pritzker, both Democrats.

(Reporting by Peter Szekely in New York; editing by Jonathan Oatis)