IFNG and infection: Moreover, the natural infection or parenteral (e.g., i.m or i.p.)vaccination of mice with the wP vaccine was found to induce formation of B. pertussis-specific IFN-γ and IL-17-secreting CD44+ CD69+ CD4+-resident memory T cells (TRM) that home into airway mucosa and respond to B. pertussis infection by secretion of IFN-γ and IL-17 (52, –, 54, 57, 58).