Story highlights Symone Sanders was hired in August 2015

She was one of the top African-American and female staffers on the Sanders campaign

(CNN) Symone Sanders, national press secretary for the Bernie Sanders' campaign, confirms that she has left the senator's presidential bid.

She gave her notice last week and was gone as of Sunday.

"I just believe my time with the campaign has come to an end," she said to CNN. "I'm very proud of the work we have done and am now looking forward to helping elect down-ballot Democrats and do all I can to ensure a Democrat is the 45th president of the United States."

The move comes weeks after the Democratic primary season ended, with Sanders far behind in the delegate count to presumptive Democratic nominee Hillary Clinton.

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