A quorum of the board shall consist of the majority of the board members. In determining whether or not a quorum is present, vacant positions on the board shall not be considered. The concurrence of the majority of the board members present shall be necessary to the validity of any action taken by the board.
Source:
Section 22201.2, https://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?lawCode=EDC§ionNum=22201.2..