| Abstract: | Viable eggs or activated oncospheres of Taenia pisiformis were inoculated subcutaneously into rabbits. At various intervals the developing larvae were killed by treatment with Mebendazole. Most rabbits receiving oncospheres were protected against challenge infection if they were treated with Mebendazole 1 day after injection and absolute immunity was established in all rabbits if larvae were allowed to develop for 14 days before being killed. In rabbits receiving eggs, 21 days from injection to Mebendazole treatment was required before absolute immunity developed. Eggs appear to require a period of 1–2 weeks for hatching and oncosphere activation in a subcutaneous site. The data also indicate that production of functionally protective antigens occurs early during larval developement. |
