The U.S. Supreme Court is set to hold a conference Friday to consider an NYPD detective’s challenge to New York City’s COVID-19 vaccine mandate for municipal workers. The justices could issue a decision on whether the mandate is legal and can continue to be enforced.

The vaccine mandate has faced a battery of legal challenges from city workers since it was issued under former Mayor Bill de Blasio toward the end of last year. But many of those lawsuits have centered on whether the city is properly applying religious or medical exemptions to the order, rather than the legality of the rule itself.

Mayor Eric Adams has faced renewed pressure to reconsider the requirement for municipal workers since ending the vaccine mandate for private-sector workers last month. As of mid-September, more than 1,750 workers — including health care workers and teachers — had been fired for refusing to get the COVID-19 vaccine, according to the mayor’s office. The municipal workforce consists of approximately 304,000 people.

The NYPD detective in this case, Anthony Marciano, filed a lawsuit against city officials in December alleging that the city health commissioner did not have the legal authority to issue the mandate in the first place.

The case alleged, in part, that because the vaccines available only had emergency use authorization under the U.S. Food and Drug Administration, rather than full approval at the time, their use constituted “human research.” His petition cited a New York law stating that such research could not be conducted without an individual’s “voluntary informed consent.”

“It doesn't matter if [the vaccines] work or not. We’re not taking a position on that,” said Patricia Finn, Marciano’s attorney. “The law prohibits adult mandates without informed consent in the absence of judicial due process here.”

A judge dismissed the case in a federal court in Manhattan in March, so Marciano turned to the highest judges in the nation. Supreme Court Justice Sotomayor declined an initial petition in August. But Finn resubmitted the emergency application to Justice Clarence Thomas, who accepted it last month and moved the case in front of the full Supreme Court.

Finn said that the Supreme Court’s recent decision in Dobbs v. Jackson Women’s Health Organization — the case that struck down the constitutional right to an abortion granted under Roe v. Wade — motivated her to try again. She said she was encouraged by the court’s deferral to state statutes, since the right to refuse informed consent is also granted under state law.

Attorneys for a handful of city unions — including the Uniformed Firefighters Association and the Lieutenants’ Benevolent Association — filed briefs to the Supreme Court voicing their support for Marciano’s petition.

The city’s municipal vaccine mandate has withstood multiple legal challenges. However, its opponents have had some wins recently.

A New York Supreme Court judge ruled Sept. 23 that the city must reinstate members of the Police Benevolent Association who were fired or placed on leave for refusing the COVID-19 vaccine. The union, which represents NYPD officers, argued that the city did not engage in collective bargaining over implementation of the mandate.

The judge in the case, Lyle Frank, said that at the time it was issued, the mandate was “appropriate and lawful,” but that the city has not established a legal basis for excluding employees from the workplace or imposing other adverse employment actions in its enforcement of the rule. A spokesperson for the city’s law department told NY1 that it would appeal the decision.

The mayor’s office did not respond to a request for comment on the Supreme Court conference on the Marciano case.