Vice President Kamala Harris tested negative for COVID-19 on Monday, six days after she was diagnosed with a virus case, the White House said. Harris, who is 57 and received two booster shots before testing positive, will continue wearing a mask for 10 days after exiting isolation, according to the White House. She has quarantined at Number One Observatory Circle, the vice president’s residence, since receiving positive results on multiple tests last Tuesday. “Today, the Vice President tested negative for COVID-19 on a rapid antigen test,” Kirsten Allen, the vice president’s press secretary, s…