A guard system is disclosed for protecting patients and medical health professionals from the transmission of airborne contagions during the administration of vaccinations. The system includes a frame having a generally rectangular shape; a transparent sheeting attached to the frame creating a barrier against the transmission of airborne contagions, the sheeting having a front side opposite a back side; an aperture in the transparent sheeting, the aperture sized for administering a vaccination to a patient seated on the back side of the transparent sheeting from the front side; a movable screen portion for covering at least a portion of the aperture; wherein the movable screen portion moves from a closed position to an open position to facilitate the administration of the vaccination.