WASHINGTON (NewsNation Now) — The U.S. Supreme Court Thursday struck down a vaccine mandate that would have impacted almost 80 million employees of large businesses around the country but ruled that most of the country’s health care workers will need to be vaccinated by the end of February.

The court’s conservative majority concluded that President Joe Biden’s administration overstepped its authority by seeking to impose the Occupational Safety and Health Administration’s vaccine-or-test rule on U.S. businesses with at least 100 employees.

In the health care facilities case, the court’s differently comprised majority concluded that the regulation “fits neatly” within the power Congress conferred on the government to impose conditions on Medicaid and Medicare funds, which includes policies that protect health and safety.

“After all, ensuring that providers take steps to avoid transmitting a dangerous virus to their patients is consistent with the fundamental principle of the medical profession: first, do no harm,” the court said.

The 5-4 vote upheld the health care worker rule, which requires vaccination for about 10.3 million workers at 76,000 health care facilities including hospitals and nursing homes that accept money from the Medicare and Medicaid government health insurance programs for elderly, disabled and low-income Americans. Two conservatives, Chief Justice John Roberts and Justice Brett Kavanaugh, joined the liberals in the majority in that case.

The rule has medical and religious exemptions.

In a statement, Biden said the court’s decision allowing the health care worker mandate “will save lives” and that his administration will enforce it.

Four conservative justices dissented from the health care facility decision, concluding that Congress had not given the federal agency the authority to require inoculations for millions of health care workers. In one dissent, Justice Samuel Alito doubted that the agency can “put more than 10 million health care workers to the choice of their jobs or an irreversible medical treatment.”

The justices lifted orders by federal judges in Missouri and Louisiana blocking the policy in 24 states, allowing the administration to enforce it nearly nationwide. Enforcement was blocked in Texas by a lower court in separate litigation, not at issue in the case before the Supreme Court.