Any vacancy in Council shall be filled by appointment by majority vote of the remaining members of Council within forty-five (45) days of such vacancy. The Council President shall report the notice of vacancy at the next Regular Council meeting after the Council President has learned that such vacancy will occur. If such vacancy is not filled within forty-five (45) days, the Mayor shall fill it by appointment. Such appointee shall hold office for the unexpired term of the member whose office is filled and shall have all the rights, powers and duties of elected Councilmembers. If the office of Council President, Vice President, or a Councilmember appointed to of a Board or Commission becomes vacant, it shall be promptly filled.