In an experiment you develop immune response in mice against salmonella flagellar antigen. However, you observe the infection still persisted. Which if a likely possibility if immune system is functioning properly?

Q. In an experiment you develop immune response in mice against salmonella flagellar antigen. However, you observe the infection still persisted. Which if a likely possibility if immune system is functioning properly?

A.            Salmonella shed its flagella

B.            The antigen lost its specificity gradually

C.            The flagella antigen changed

D.            Infection was not due to salmonella

Answer: The flagella antigen changed