"I'm nervous about it," said Allison Douma, 24, out walking her dogs in Washington, D.C., and wearing a mask. She was fully vaccinated last month. "I just don't feel safe because vaccination rates are going down, and I'm worried about the mutations." In New York City, Maggie Cantrick, 39, who works at an arts center, said she was not ready to lose her mask in places such as a grocery story. "I am fully vaccinated - I can just take off my mask? This is crazy!" she said. U.S. supermarket chain Kroger Co said it will continue to require customers to wear masks. "We are reviewing current safety practices, the CDC’s latest guidance, and soliciting feedback from associates to guide the next phase of our policy," the company said in a statement.