In light of the new guidance, Main Line Health says it is no longer allowing cloth masks to be worn by employees or visitors in any of its locations or administrative areas.
"Given the high transmissibility of this variant and based on guidance from the CDC and our infectious disease clinical team, the protections offered by surgical and/or isolation masks outweigh those provided by cloth masking," said Main Line Health in a letter to the community.
SEE ALSO: CDC encourages more Americans to wear N95 masks to slow spread of COVID-19
N95 and KN95 masks can be costly and harder to find, even as the U.S. government has built up a stockpile of 737 million N95s to ensure first responders don't run out. President Joe Biden said last week he is developing a plan to make the higher quality masks more widely available.
Earlier this month, Main Line Health announced a two-week pause on all elective procedures and surgeries.
The health system expects procedures to resume on January 21.
"We will continue to evaluate the situation and if anything changes in either direction, updated information will be available on our Main Line Health website and your physician will immediately be made aware," officials said.
ABC News contributed to this report.