Pidotimod is a dipeptide immunostimulant with biological activity on both the adaptive and the innate immune responses. Pidotimod has been reported to modulate airway epithelial cells functions involved in host-virus interaction possibly through NF-kB activation, promote functional maturation of dendritic cells, and facilitate M2 macrophage polarization and function. Pidotimod has been investigated for use to increase response to recurrent respiratory infections primarily in children.