A federal judge in Missouri has temporarily blocked a federal agency’s Covid vaccine mandate for most health care workers in Iowa and nine other states.

The Centers for Medicare and Medicaid Services issued the requirement that U.S. health care facilities ensure staff are fully vaccinated by January 4th. Hospitals, clinics and nursing homes that failed to do so were at risk of losing the federal funding that pays the bills for Medicare and Medicaid patients.

Iowa Governor Kim Reynolds joined a lawsuit challenging the requirement earlier this month. The judge says the vaccination rule has vast economic and political significance and should have been approved by congress.