IL-17 has been linked with IgA-mediated protection in the nasal cavity of mice induced by attenuated vaccine B. pertussis strain BPZE1.45 Furthermore, circulating IgG induced by maternal immunization can prevent pertussis deaths in infants.52 However, we found significantly stronger B. pertussis-specific IgA and IgG2c antibody responses in lungs and nasal washes of Il17A−/− mice compared with WT mice during primary or re-infection with B. pertussis. The gene discussed is IL17A; the disease is infection.