New York City Mayor Bill de Blasio announced last Wednesday the enactment of a COVID-19 vaccine mandate for all city employees, requiring them to receive the first dose by Nov. 1 or be placed on unpaid leave until they provide proof of vaccination. The new mandate will not include a testing option as a substitute for getting vaccinated.

City employees will gain an extra $500 in their paycheck if they receive their first COVID-19 shot at a city-run vaccination site by Oct. 29, NBC New York reports.

De Blasio released a statement following the decision, speaking about New York City’s progress in tackling the pandemic while stressing the importance of getting vaccinated.

“There is no greater privilege than serving the people of New York City, and that privilege comes with a responsibility to keep yourself and your community safe,” de Blasio said.

“We have led the way against COVID-19 – from fighting for the right to vaccinate frontline workers, to providing nation-leading incentives, to creating the Key to NYC mandate. As we continue our recovery for all of us, city workers have been a daily inspiration. Now is the time for them to show their city the path out of this pandemic once and for all.”

New York City’s Deputy Mayor of Health and Human Services Melanie Hartzog also released a statement, echoing de Blasio’s stance on the importance of the public getting vaccinated.

“Vaccinations are critical to combatting the COVID-19 pandemic. This mandate is a bold step that protects our families, friends, and communities, including those that are not yet eligible for the vaccine such as our city’s youngest residents,” Hartzog said.

“It builds on our continued leadership and innovative strategies to fighting this pandemic and bring us a step closer to a recovery for all.”

The city’s vaccine mandate affects more than 160,000 workers, including police officers, firefighters and correctional officers who have not yet received their first shot of the COVID-19 vaccine. 70% of city employees, however, have already received at least one vaccine dose, according to NBC New York.

Several union leaders that represent city workers who will be impacted by the mandate expect to see hundreds of thousands of employees leave their jobs rather than to get vaccinated, The Wall Street Journal reports.

“You’ll have police officers walking off—firefighters, EMTs and paramedics walking off. Who’s going to respond to these calls?” Oren Barzilay,  FDNY EMS Local 2507 President, said according to The Wall Street Journal. “We are in for dark days in our city, and it’s crazy.”

New York City’s largest police union, the Police Benevolent Association, said getting vaccinated is a “personal medical decision” that officers should make with their respective doctors.  “Now that the city has moved to unilaterally impose a mandate, we will proceed with legal action to protect our members’ rights,” Police Benevolent Association President Patrick Lynch said, according to the Associated Press.

Andrew Ansbro, president of the FDNY Uniformed Firefighters Association, stated he informed members that “if they choose not to get vaccinated, they must still report to duty.” Nearly 45% of FDNY firefighters are unvaccinated, Ansbro said to NBC New York. He also said that the workers want testing to continue.

New York City is not the only city to enforce a mandate on its employees.

San Francisco enacted a similar mandate for its 35,000 city workers, which goes into effect on Nov. 1. Chicago and Los Angeles have been advocating for its workers to get vaccinated, while Washington and Massachusetts are requiring state employees to be fully vaccinated.