The Supreme Court has stopped the Biden administration from enforcing a requirement that employees at large businesses be vaccinated against COVID-19 or undergo weekly testing and wear a mask on the job. At the same time, the court is allowing the administration to proceed with a vaccine mandate for most health care workers in the U.S. The court’s orders Thursday during a spike in coronavirus cases was a mixed bag for the administration’s efforts to boost the vaccination rate. The court’s conservative majority concluded the 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. More than 80 million people would have been affected.