Adoptive transfer results demonstrated EPS301-adjuvanted vaccination immunized lung CD4 T cells and γδ T cells were crucial for anti-P. aeruginosa induced pneumonia, but immunized spleen CD4 T cells and γδ T cells were dispensable, which, in part, explained the traditional parenteral vaccine were failed to P. aeruginosa pneumonia because of mainly induced systemic immune response. This evidence concerns the gene CD4 and susceptibility to pneumonia measurement.