The Supreme Court blocked the Biden administration from enforcing its emergency rule mandating that workers at large businesses get vaccinated or undergo regular testing for COVID-19, a major setback for the presidents national vaccination effort.

However, the court decided to allow the administration to proceed with a vaccine mandate for health care workers at federally funded facilities.

The justices decision to intervene and halt one of the vaccine regulations has major public health implications amid a surge in coronavirus cases due to the omicron variant. The White House hoped the rule, issued through the Occupational Safety and Health Administration, would protect workers against COVID-19 transmission and encourage holdouts to get vaccinated.

The justices ruled 6-3 in favor of halting OSHAs vaccine-or-test rule, with the courts six conservatives in the majority and the three liberals dissenting. They ruled 5-4 in favor of letting the health care rule proceed, with Chief Justice John Roberts and Justice Brett Kavanaugh breaking with their conservative colleagues to join the liberals.

The OSHA regulation requires that employers with at least 100 workers implement programs in which those workers show proof of vaccination or provide a negative COVID-19 test each week. The administration estimates it would cover 84 million workers, mostly in the private sector.

Enforcement of the testing provision was slated to begin on Feb. 9.

Business groups and state GOP officials filed lawsuits aimed at blocking the rule, arguing that it went beyond OSHAs legal power and would hurt the economy by prompting workers to quit their jobs. Lower courts disagreed on whether the rule was within OSHAs authority.

In their ruling, the majority said the opponents of the OSHA rule were likely to prevail in court, and so the justices decision prevents the rule from going into effect while the litigation plays out. In an opinion joined by justices Clarence Thomas and Samuel Alito, Justice Neil Gorsuch wrote that Congress has nowhere clearly assigned so much power to OSHA to institute such a requirement for employers.

Yet that is precisely what the agency seeks to do nowregulate not just what happens inside the workplace but induce individuals to undertake a medical procedure that affects their lives outside the workplace, Gorsuch wrote.