Similarly, administration of heat-killed whole cell B. pertussis during sensitization and before OVA challenge also significantly suppressed airway eosinophilia and lung inflammation, which correlated with suppressed Th2 cytokine (IL-4 or IL-5) responses without the increased Th1 cytokine (IL-12 or IFN-γ) levels [26]. Here, IL4 is linked to inflammation.