WASHINGTON -- Amtrak will need to reduce service in January unless more employees get vaccinated against COVID-19, the passenger rail system’s president says.

       Stephen Gardner says about 95% of Amtrak workers are at least partially vaccinated. The rest face a Jan. 4 deadline that the Biden administration set for employees of federal contractors.

       If enough employees resist getting the shots, Amtrak anticipates '"proactively needing to temporarily reduce some train frequencies across our network in January,” Gardner told a congressional panel Thursday.

       Gardner said any service reductions would last until Amtrak is able to fully staff up, which he said could last until March.

       The official’s warning about service cuts comes as Amtrak tries to recover from a steep drop in passenger traffic that started last year. Gardner said Amtrak has restored most service and about 70% of passenger traffic has returned.

       Amtrak said in August that all employees would need to get vaccinated or be tested weekly for COVID-19. In September, President Joe Biden ordered that federal workers and employees of federal contractors be fully vaccinated by Dec. 8, a deadline that was later delayed until Jan. 4.

       This week, a federal judge in Georgia blocked the administration from enforcing the mandate, saying that Biden exceeded his authority in issuing the executive order for vaccinations. The ruling expanded one issued by a federal judge in Kentucky that was limited to contractors in three states.

       Separately, other judges have held up Biden’s vaccine mandates for health care workers and companies with at least 100 employees.