The term of office of members of the board shall be four years beginning on the day of the general election at which they are elected, or if elected at a primary election, on the day of the general election immediately following the primary election at which they are elected, and ending on the day of the second general election after their election. Members of the board may be reelected without restriction as to the number of terms.

Any vacancy that may occur through any cause other than the expiration of the term of office shall be filled in accordance with section 17-7.