Denise King, a staff member at Crown Heights Center for Nursing and Rehabilitation, a nursing home facility, receives the Pfizer-BioNTech coronavirus disease (COVID-19) vaccine from Walgreens Pharmacist Annette Marshall, in Brooklyn, New York, December 22, 2020.

The Centers for Disease Control and Prevention said Wednesday that an average of 60% of nursing home personnel in the U.S. are vaccinated against Covid, a rate officials say leaves the care facilities at higher risk for outbreaks among residents and staff.

Vaccinating more employees is one of the most important steps nursing homes can take to keep residents safe, CDC epidemiologist Dr. Rachel Slayton said at a meeting of the agency's Advisory Committee on Immunization Practices on Wednesday. Though administering booster doses to residents can help limit cases, Slayton said nursing homes remain vulnerable to outbreaks when staff members choose not to vaccinate.