IL17A and infection: In contrast, supplementation of the inoculum with either IFN-γ or IL-17A but not IL-22 during infection was able to lower the incidence of abscess to 50% and reduce the median bacterial burden to 55 or 208 CFU, whereas coadministration of both IFN- γ and IL-17A resulted in almost complete protection (9/10 mice were free of abscess 4 days postinfection) (Fig. 5A).