Boston is appealing a judge's order blocking its COVID-19 vaccination mandate on certain classes of firefighters and police officers.

Democratic Mayor Michelle Wu's office on Friday appealed a state Appeals Court ruling from earlier this month declaring the city's mandate couldn't be enforced on members of the city firefighters union and two police officers unions until their ongoing legal challenge is resolved.

City workers must be vaccinated or face termination under the mandate.

The Boston Police Superior Officer Federation, one of the unions involved in the suit, says its “deeply disappointed” in the city’s latest legal maneuver.