In Gilbert v. Richardson, 264 Ga. 744 (452 SE2d 476) (1994), the Georgia Supreme Court recognized that "under the doctrine of respondeat superior, a principal has no defense based on an agent's immunity from civil liability for an act committed in the course of employment." Id. at 753-754 (7). This rule, which had been applied in some of this Court's prior cases involving common law immunities, stems from the principle that "immunities, unlike privileges, are not delegable and are available as a defense only to persons who have them. . . ." Id. at 754 (7), citing Restatement (Second) of Agency, 217 (b) (ii) (1958). In Gilbert, the Supreme Court applied the rule to hold that the official immunity conferred by the State Constitution on public officers and employees "does not protect a governmental entity from liability under the doctrine of respondeat superior." Id.