The survival of adult Litomosoides carinii transplanted into cotton rats previously injected with irradiated stage 3 larvae.

Adult Litomosoides carinii were surgically removed from the pleural cavities of normal cotton rats which had been infected 35 days previously by the inoculation of normal stage 3 larvae. Groups of 20 such worms were then transplanted into either the pleural cavities of other normal, uninfected cotton rats or into the pleural cavities of cotton rats which had previously received, by subcutaneous injection, either 3 X 50 L3 which had been exposed to 40 krads Cobalt 60 irradiation or 1 X 50 L3 irradiated at 16.2 krads. Cotton rats vaccinated with irradiated L3 prior to transplant accepted transferred worms for at least 65 days whereas uninfected cotton rats soon encapsulated and destroyed the transferred worms. Microfilariae were detected in the pleural exudate and peripheral blood of vaccinated cotton rats but not in that of unvaccinated cotton rats.