Notably, intranasal immunization in mice protects mice against multiple bacterial pneumonia (e.g., P. aeruginosa, S. pneumonia) in an antibody-independent but IL-17–dependent manner (Wu et al., 2012; Wang et al., 2017), which suggest the feasibility of development a broadly protective vaccine against bacterial pneumonia by targeting lung Th17 cells. Here, IL17A is linked to susceptibility to pneumonia measurement.