Hello, I immunized my mice with an acellular vaccine then I challenged them with Bordetella pertussis by aerosol rout at 2 weeks after second immunization. I sacrificed them and collected their BAL at 10 days after aerosol challenge and measurement of cytokines(IFN-gamma and IL-4 and IL-17) by ELISA but I coulden't detect them in BAL.now, I want to know this result is correct or no?