Kenyon R H, McManus A T
Infect Immun. 1974 May;9(5):966-8. doi: 10.1128/iai.9.5.966-968.1974.
Rickettsia rickettsii and R. australis formed infectious antibody complexes when reacted with homologous convalescent serum. The addition of antiglobulin to these complexes showed neutralization of plaques proportional to the concentration of rickettsial immune serum.