Cell-mediated immune response to Coxiella burnetii antigens in Q fever convalescents and vaccinees.

Cellular immunity against phase I and II Coxiella burnetii antigens was evaluated by the lymphocyte blast transformation test in a) Q fever convalescents; b) persons immunized with a chemovaccine against Q fever; and c) control persons. The first two groups consisted of workers in a ricketsiology department. Of the 9 convalescents, all (100%) were positive against phase I antigen and 4 (44.4%) against phase II antigen. Of the 22 vaccinees, 77.3% were positive against phase I antigen and all were negative against phase II antigen. All 10 controls were negative against both antigens.