A leading Chicago police union opposed an impending mandate from Mayor Lori Lightfoot that requires all city officers to get the COVID-19 vaccine.

John Catanzara, president of the Chicago Fraternal Order of Police, said his group is “100% against mandated vaccines for our members,” according to a statement given to Fox 32 .

“This vaccine has no studies for long-term side effects or consequences. None,” Catanzara told the Chicago Sun-Times . “To mandate anybody to get that vaccine, without that data as a baseline , amongst other issues, is a ‘Hell, no’ for us.”

He also insisted all police unions in the city oppose such a mandate.