Preliminary report on the stimulation of immunity to the larval stage of Taenia multiceps.

The efficacy of Oncosphere Secretory Antigen (OSA) in protecting sheep against the larval stage of Taenia multiceps was assessed in 47 sheep in 2 trials. In the pilot trial no cerebral coenuri were found in 3 sheep which were treated with OSA 28 and 14 days before challenge with 6 000 eggs of T. multiceps. Cerebral coenuri were present in 3 untreated controls. In the second experiment 30 sheep were similarly treated with OSA and challenged with 5 000 eggs of T. multiceps, while 11 sheep served as untreated controls. At necropsy either developing coenuri or degenerate lesions were present in the brain of 5 (16,6%) of the 30 vaccinated animals while 8 out of 11 (72,7%) of the untreated animals had cerebral coenuri or degenerate lesions in the brain. It is concluded that OSA may be used to protect animals against cerebral coenuriosis.