REV. LIZ WALKER of the Roxbury Presbyterian Church said on Wednesday that she was honored to be a part of the state’s effort to roll out a COVID-19 vaccine – she called it “a piece of history” – but she warned that it won’t be easy in communities of color.

“We are aware of the troublesome trust factor in our country and in many communities,” she said at a State House press conference with Gov. Charlie Baker and other officials. “We know that trust cannot be earned in one news conference or in one statement, but we are all committed to the work of engaging residents and community leaders in as many ways as we can and be a part of this effort.”

Walker, who serves on the governor’s vaccine advisory panel, said the coronavirus pandemic has accentuated the fears of people of color. “I work specifically with a group of people who have been traumatized by violence, by racism, by systems, by history, and so they suffer disproportionately anyway,” she said.

Walker recently hosted Dr. Anthony Fauci, the director of the National Institute of Allergy and Infectious Diseases, for a virtual talk about COVID-19 that attracted more than 2,000 people. Walker said Fauci’s speech highlighted for her the challenges facing Massachusetts and the nation in convincing people of color to take the vaccine.

”Most people were impressed that Dr. Fauci showed up to speak directly to the community,” Walker said. “He was there. He showed up.”

But Walker said Fauci didn’t sway everyone. In an informal survey of less than 20 of her parishioners, Walker said about half were impressed with what they heard and inspired to learn more and the other half remained skeptical.

“That’s probably indicative of a lot of people in our communities,” she said. “I think there’s a lot of skepticism still. It’s going to take a lot of work….My prayer is that I have earned enough trust in my community to help people make good decisions.”