Failure of Q fever phase I corpuscular vaccine to influence the persistence and reactivation of Coxiella burnetii infection in mouse and guinea pig tissues.

In mice and guinea pigs infected with Coxiella burnetii, accumulation of large numbers of rickettsiae in the spleen and liver occurring at the early stages of infection was followed by clearing of these organs from the infectious agent but by its persistence in kidneys and reproductive tract at later intervals. The persistence of C. burnetii was not affected when one to six months-infected mice or guinea pigs were immunized with 100 or 500 micrograms of Q fever phase I corpuscular vaccine. Administration of the vaccine also did not substantially influence the reactivation of C. burnetii infection elicited in mice by parturition or developing in mice and guinea pigs upon treatment with cortisone or cyclophosphamide (CPA). Some differences observed between groups of immunized or non-immunized animals were only quantitative in nature. The possibility to disbalance the steady state of persisting C. burnetii in the host tissues by inhibition or stimulation of the immune response is discussed.