Some of the largest U.S. hospital systems have dropped Covid-19 vaccine mandates for staff after a federal judge temporarily halted a Biden administration mandate that healthcare workers get the shots.

Hospital operators including HCA Healthcare Inc. HCA 0.88% and Tenet Healthcare Corp. THC 1.62% as well as nonprofits AdventHealth and the Cleveland Clinic are dropping the mandates. Labor costs in the industry have soared, and hospitals struggled to retain enough nurses, technicians and even janitors to handle higher hospitalizations in recent months as the Delta variant raged. Vaccine mandates have been a factor constraining the supply of healthcare workers, according to hospital executives, public-health authorities and nursing groups.

Many hospitals already struggled to find workers, including nurses, before the pandemic. The shortages were compounded by burnout among many medical workers and the lure of high pay rates offered to nurses who travel to hot spots on short-term contracts.