Appearance of cellular and humoral immunity in guinea pigs after infection with Coxiella burnetii administered in small-particle aerosols.

The development of humoral and cell-mediated immune responses was studied in guinea pigs infected with Coxiella burnetti administered in small-particle aerosols. Direct macrophage migration inhibition was observed in cultured peritoneal exudate cells as early as 3 days after exposure. Maximum inhibition of macrophages cultured with phase I or II antigen occurred 14 to 21 days postexposure and persisted through 35 days. This inhibitory action was no longer detectable at 42 days. Serum antibody to the phase II antigen of C. burnetii was detected at 14 days, and serum antibody to phase I antigen was detected at 21 days, 18 days after the cell-mediated immune response.