Amid the rising numbers of infections, some state and local leaders are now recommending that masks to be worn indoors even by those who are vaccinated.

Health officials in Seattle and King County in Washington noted Friday that the Delta variant’s prevalence in the US was 1.4% on May 13 when the CDC lifted mask requirements for vaccinated people. Right now, Delta makes up 56% of King County’s known infections and the figure is expected to rise.

“I know this is frustrating and maybe disappointing to many, it certainly is to me,” Dr. Jeffrey Duchin, health officer for the Seattle and King County public health department said Friday.

“And I acknowledged that the change in communication,” he said, “has been a real problem nationally, but we in public health have an obligation to be realistic about the changing situation and provide the best guidance possible.”