The use of gamma-radiation-attenuated larvae of Gaigeria pachyscelis Railliet and Henry, 1910, for vaccination in lambs.

The results of vaccination trial in lambs with gamma-irradiated infective larvae of Gaigeria pachyscelis are described. A single percutaneous (P/C) vaccination of lambs with 2000 infective larvae irradiated at 40 Kr induced the development of resistance. The vaccinated lambs successfully resisted a lethal challenge infection of 5000 non-irradiated larvae 3 months later. In the vaccinated lambs, the manifestations of resistance were shown by marked reduction in the worm establishment, development of retarded and functionally sterile worms and absence of clinical signs of hookworm disease after the challenge infection.