Masks ‘don’t work,’ Grapevine-Colleyville ISD trustee says as district changes COVID-19 protocols The district is following CDC guidelines and keeping its mask policy after a meeting where board member Casey Ford said ‘science does not prove’ that masks work. Grapevine-Colleyville made changes to its COVID-19 protocols but will continue to require students and staff to wear masks.(Tom Fox / Staff Photographer) Grapevine-Colleyville ISD is changing its COVID-19 protocols following a vote by its board Monday night. While the use of plexiglass is now optional at the elementary level, a mask mandate will continue to be in place, despite board trustee Casey Ford’s remarks that he believes they do not work, which contradicts what the Centers for Disease Control and Prevention and medical experts have said.