Vaccination of young lambs by means of a protein fraction extracted from adult Haemonchus contortus.
Lambs aged 48-150 days which had been injected with extracts enriched in a functional antigen (contortin) obtained from adult Haemonchus contortus developed specific circulating antibodies and were less susceptible to haemonchosis when challenged 1 month later with a single dose of 20,000-25,000 infective 3rd-stage larvae. Sera from 18 out of a total of 19 lambs injected with the extract contained precipitating antibodies to 2-5 components of the extract. None of these lambs died. The one extract-injected lamb which did not develop antibodies and 9 of the 13 lambs used as controls died of haemonchosis. The average weight of worms recovered was 1.45 g from the immune lambs and 5.72 g from the non-immune lambs.
D000818:Animals; D000917:Antibody Formation; D000947:Antigens, Helminth / Q000276:immunology*; D005260:Female; D006188:Haemonchiasis / Q000276:immunology / Q000662:veterinary*; D006189:Haemonchus / Q000276:immunology*; D008297:Male; D010270:Parasite Egg Count; D012756:Sheep; D012757:Sheep Diseases / Q000276:immunology*; D014251:Trichostrongyloidea / Q000276:immunology*; D014252:Trichostrongyloidiasis / Q000662:veterinary*; D014611:Vaccination / Q000662:veterinary; D014612:Vaccines / Q000276:immunology*
D000947:Antigens, Helminth; D014612:Vaccines; C052800:contortin