This enhanced macrophage recruitment was lost in Ag and CpG-immunized IFN-γ−/− but not in IL-17A−/− mice (Figure S8), providing indirect evidence that immunization with pertussis antigens in combination with a Th1-promoting adjuvant promote recruitment of macrophages to the lungs post challenge with B. pertussis. This evidence concerns the gene IFNG and pertussis.