Anti-oncospheral antibodies in the serum of lambs experimentally infected with either Taenia ovis or Taenia hydatigena.

Using a peroxidase micro-enzyme--linked--immunosorbent assay (ELISA) method anti-oncospheral antibodies were demonstrated in sera from four lambs after primary and challenge infections with Taenia ovis or T. hydatigena. Antibodies assayed using homologous oncospheral antigen (OA) reached a peak by 3-4 weeks after primary infection and at 1-3 weeks post-challenge infection, but waned to pre-infective, "background" levels by 8-12 weeks after each infection. Antibodies assayed against antigens in strobilar or cystic larval extracts persisted for long periods after the initial infections and exhibited different kinetics of response from those demonstrated against OA. These antibodies showed increased levels after challenge infection. Oncospheral antigens did not seem to be species specific although they appeared to elicit a stage-specific response. It is suggested that the anti-oncospheral antibody response could be associated with protective or "functional" antibody.