The U.S. Supreme Court has declined to hear arguments in a lawsuit that sought to challenge Maine’s COVID-19 vaccine mandate for health workers.

Justices did not explain their decision in court papers on Tuesday. The court had already turned down two emergency applications that sought to stop the mandate from going into effect.

The vaccine requirement in Maine went into effect in October. Unnamed workers sued the state to try to require religious exemptions from the vaccine law.

Supporters of the rule have pointed out that Maine has required health facilities to make sure workers are vaccinated against other diseases for decades.