Boston Mayor Michelle Wu again pushed back the deadline for city employees to get vaccinated Sunday, giving them until at least Jan. 30 to get vaccinated against COVID-19.

The mandate was supposed to go into effect Monday following Wu’s first extension of the deadline, which was initially set for Jan. 15. Wu tightened the mandate in December to require vaccination for those who don’t have a medical or religious exemption. Under former acting Mayor Kim Janey, city employees were allowed to get tested weekly in lieu of vaccination.

A press release from her office said that “no employees will be disciplined or placed on unpaid leave” between Jan. 25 and Jan. 30

As of Sunday afternoon, Wu’s office said in the press release, 18,265 municipal workers have received at least one shot of a COVID-19 vaccine — an increase of nearly 800 employees in the last nine days.

Some employees have fought hard against the mandate. Two police unions and a firefighters' union brought a court case against the city to halt its implementation, which a judge threw out earlier this month. Others have brought the fight to Wu, protesting during the new City Councilors’ inauguration and outside her Roslindale home.

Wu will hold a press conference at City Hall Monday morning at 10 a.m. to give an update on the vaccine requirement.