Mississippi Code
Board of Directors
§ 79-4-8.10. Vacancy on board

Unless the articles of incorporation provide otherwise, if a vacancy occurs on a board of directors, including a vacancy resulting from an increase in the number of directors:
If the vacant office was held by a director elected by a voting group of shareholders, only the holders of shares of that voting group are entitled to fill the vacancy if it is filled by the shareholders and only the directors elected by that voting group are entitled to fill the vacancy if it is filled by the director.
A vacancy that will occur at a specific later date (by reason of a resignation effective at a later date under Section 79-4-8.07(b) or otherwise) may be filled before the vacancy occurs but the new director may not take office until the vacancy occurs.