The Philadelphia school board on Tuesday mandated COVID-19 vaccines for all staffers, a move that will affect more than 20,000 workers.

The school board unanimously approved a resolution directing Superintendent William R. Hite Jr. to develop and implement an inoculation plan for staff, contracted personnel, and service providers.

The vaccination deadline was not set Tuesday night. Hite said negotiations with the district’s five unions will begin Wednesday, with progressive discipline for those who refuse to comply, resulting in “job action,” the superintendent said.

Employees will be able to submit requests for exemption, “which may be based on certain documented medical circumstances or sincerely held religious beliefs,” the board decided.

Both Hite and Cheryl Bettigole, acting city health commissioner, said the mandate was necessary to protect public health, especially given the roughly 80,000 city students too young to be vaccinated and the fact that most district schools will not be able to socially distance children.

“We’ve reached a time when vaccine mandates are necessary,” Bettigole told the board.

“This is the path forward,” board member Mallory Fix Lopez said. “We cannot say that we have done absolutely everything possible until we have a vaccine mandate.”

With rising coronavirus case counts, the spread of the delta variant, and the looming start of the school year, more schools throughout the nation are taking such actions. Gov. Phil Murphy has ordered all New Jersey teachers to be vaccinated; the New York City public school system, the nation’s largest, is also requiring inoculation.

Whether Philadelphia will give teachers and other staff a testing loophole if they choose not to get vaccinated also remains to be seen. New Jersey teachers, for instance, can submit to COVID-19 testing at least once or twice a week in lieu of vaccination.

Philadelphia had already said it will test its staff for the virus weekly, and Hite declared the mask mandate for all staff and students earlier this summer.

Any mandate won’t be in place by the start of the school year; Philadelphia’s 120,000 students are set to return to school Tuesday, many of them seeing the inside of a classroom for the first time in almost 18 months.

The superintendent said families will not be able to get information about whether their child’s teachers have been vaccinated; such information is confidential.

The PFT has estimated that most of its 13,000 members — teachers, counselors, nurses, secretaries, and other support staff — are already inoculated, but it does not have hard data.

But not all staff are in favor of the mandate. Christine Heying, who’s both a teacher and a parent, said she can’t receive the vaccine for medical reasons and urged the board to reject the mandate, which she called “a civil rights and equity issue.”

“Right now, I’m more scared of my employer than I am of catching COVID,” Heying said.

Teacher Jessica Soto said she believes the district has sufficient COVID-19 safety measures in place.

“Those who wanted the inoculation have already had it,” Soto said in written testimony. “The PFT and PSD should not be putting teachers in a position where they have to choose between a medical procedure or their jobs, even with exemptions in place.”

PFT president Jerry Jordan supports the mandate, and said in a statement that “a multilayered mitigation strategy is absolutely key — vaccines, universal masking, and universal testing.” (The teachers’ union does want the district to go further, however; it joined nine members of City Council in calling for the district to implement regular testing of asymptomatic students.)

But at least one other district union signaled its disapproval with the mandate.

Nicole Hunt, president of Unite Here Local 634, which represents cafeteria employees and school-climate staff, said the district “should not be telling people what to do with their bodies.”

Hunt said the mandate would be burdensome to the district’s lowest-paid workers.

“I fear this decision will have people resign if you make this a requirement of their jobs,” Hunt told the board Tuesday night.

Still, the vaccine mandate received broad support from others, including other district staff, and many parents.

Jill Johnson, a nurse and mother of children in district schools, said she supports the inoculation mandate.

“The first thing we did as a city when coronavirus began was to shut down schools,” Johnson wrote in testimony to the board. “We knew immediately that our children needed our help to stay safe. A year a half later, we have so much information to support the decision to continue to protect our children. All of the things we already have in place will only be more effective if we add the protection of vaccination for all employees.”