NEW YORK (CBSNewYork) – New York City’s vaccine mandate for public school teachers and staff can once again move forward after the latest ruling from a federal appeals court.

Now, the city is setting a new deadline, as some workers say their fight is not over.

READ MORE: New York City Public School Sports Teams May Allow Spectators

“Vaccine mandates, they not only work, they are winning in court,” Mayor Bill de Blasio said Tuesday. “Every single time, the city of New York wins.”

The mayor was victorious Tuesday after the federal appeals court removed a temporary block on the mandate. Teachers and staff have to get their first shot by 5 p.m. Friday or face termination.

“That means that all the court challenges are now exhausted,” de Blasio said. “So by Monday morning, 100% of the staff of the adults in our schools will be vaccinated.”

The ruling reversed a previous court decision that blocked the mandate last Friday.

“Vaccinations are our strongest tool in the fight against COVID-19. This ruling is on the right side of the law,” a spokesperson for the Department of Education said in a statement.

Most parents Dias spoke with agreed, sharing the common bond of safety.

“For me, and I think a lot of parents, is that everybody has the safest environment in which to learn,” one parent said.

“I need a safe environment for my kid, who is not vaccinated. It’s not her choice,” said Amin Erfani, of Washington Heights.

READ MORE: Moderna, Johnson & Johnson COVID-19 Vaccine Booster Shots Greenlighted By CDC

COVID VACCINE

An attorney for teachers opposing the mandate said they will now petition the U.S. Supreme Court.

“It’s almost as though the dictator is just feeling slighted and trying to do everything in his power to ruin the people who just don’t agree with him,” Staten Island special education teacher Rachel Maniscalco said  of the mayor.

While the teachers union estimate 97% of teachers have been vaccinated, it’s still worried about using substitutes, who may not be qualified, to fill vacancies.

“You have to match the teacher with the subject, with the grade level,” said United Federation of Teachers President Michael Mulgrew. “I think schools are just saying, ‘We need an adult with a license inside of a room to cover the safety needs.'”

CORONAVIRUS PANDEMIC

Staffing shortages may also be a problem in other roles. The union said in part, “Only about one-third believe that as of now their schools can open without disruption.”

However, some parents remain hopeful.

“Being that we went through quite a hellish last year… I have full confidence that they’re going to be able to adapt,” Upper West Side parent Peter Okkerse said.

MORE NEWS: Mayor De Blasio Doubles Down On Municipal Workers Vaccine Mandate: 'We Have Contingency Plans In Place'

The DOE estimates around 13% of its employees are still not vaccinated.

John Dias