Circulating immune complexes in rabbits surviving rinderpest virus infection.

Circulating immune complexes (CICs) precipitated from the sera of rabbits recovered from infection with rabbit virulent (lapinized) rinderpest virus (RPV) were found to contain RPV antigen and rabbit IgG. The CICs persisted for at least 77 days post infection. The CICs and the antigen isolated from them by chromatography on Sepharose-6B were found to be non-infectious. RPV-specific antibodies could be detected in the antisera raised in rabbits against the CICs and the isolated antigen. Furthermore, the antigenic content of CICs competed with the attenuated strain and the virulent isolate Hisar of RPV in competition ELISA. Identical CICs were not detected in the sera of calves vaccinated with RBOK strain.